Costco Nut and Seed Brittle (Easy Copycat Recipe)
Costco nut and seed brittle is one of those snacks that disappears fast once it hits the counter. This copycat version gives you the same crunchy, caramel-coated clusters of nuts and seeds at home, for a fraction of the cost, and you can tweak the mix to whatever you have in the pantry.
It comes together in one saucepan with no candy thermometer required. If you can stir and keep an eye on a pan, you can make this.
Why I Love This Recipe
The caramel here gets genuinely dark and slightly bitter before the nuts go in, which gives the brittle depth instead of just sweetness. That balance is what keeps you going back for another piece.
It also cools into proper brittle: thin, glassy, and satisfying to crack apart. No soft or sticky patches when you follow the timing.
This is the version I keep coming back to for gift boxes and holiday tins because it holds up well at room temperature for over a week.
Recipe Ingredients
- 1 cup (200g) granulated sugar – the base of the caramel; do not substitute powdered sugar
- 1/3 cup (80ml) water – helps the sugar dissolve evenly before it starts to colour
- 2 tbsp (40g) honey – adds a floral note and helps prevent crystallisation
- 2 tbsp (28g) unsalted butter – gives the caramel richness and a slightly glossy finish
- 1/2 tsp fine sea salt – stir in at the end for a clean salty hit against the sweet
- 1/4 tsp baking soda – aerates the caramel slightly so the brittle is crackable, not rock-hard
- 1/2 cup (70g) raw almonds – whole or roughly chopped; roasted works but reduce oven time
- 1/2 cup (65g) raw cashews – their mild flavour lets the caramel shine
- 1/4 cup (35g) raw pumpkin seeds (pepitas) – add a green colour contrast and a lighter crunch
- 3 tbsp (30g) sunflower seeds – small and flat, they distribute through the brittle evenly
- 2 tbsp (20g) sesame seeds – toast quickly in the caramel and add a nutty, slightly bitter edge
- 1/2 tsp vanilla extract – stir in off the heat; high heat destroys the flavour
Variations / Substitutions
- Swap cashews for macadamia nuts – they add a buttery, fatty richness that makes the brittle feel more indulgent.
- Use maple syrup instead of honey – the caramel will have a deeper, woodsy flavour and is suitable for a vegan version if you also swap the butter for refined coconut oil.
- Add 1/4 tsp cayenne – a small amount adds a slow heat at the back of the throat that contrasts well with the sweet caramel.
- Swap pumpkin seeds for flaxseeds – the brittle will be slightly denser since flaxseeds are smaller and more tightly packed.
- Use salted butter instead of unsalted – reduce the added sea salt to 1/4 tsp so the brittle does not tip into too-salty territory.
- Add 2 tbsp dark chocolate chips – scatter them over the brittle right after it sets and before it fully hardens; they will melt slightly and give you a chocolate-drizzle effect.
If you enjoy making snack confections like this, you might also like a recipe for homemade candied pecans.
How To Make Nut and Seed Brittle
Step 1: Toast the Nuts and Seeds
Heat your oven to 300°F (150°C). Spread the 1/2 cup almonds, 1/2 cup cashews, 1/4 cup pumpkin seeds, 3 tbsp sunflower seeds, and 2 tbsp sesame seeds in a single layer on a dry baking sheet. Slide them in for 8 minutes, until the sesame seeds are just turning pale gold and the nuts smell warm and toasty.
Pull the pan out and set it aside, but keep the oven off. You want the nuts warm when they hit the caramel so they don’t seize it up. Cold nuts dropped into hot caramel can cause it to harden unevenly.
Step 2: Caramelise the Sugar
Line a separate large baking sheet with a silicone mat or lightly greased parchment. In a medium, heavy-bottomed saucepan over medium heat, stir together the 1 cup granulated sugar and 1/3 cup water until the sugar dissolves, about 2 minutes. Add the 2 tbsp honey and stop stirring. Let the mixture cook, swirling the pan gently every minute or so, for 10 to 14 minutes total, until the caramel reaches a deep amber colour, similar to dark orange juice.
You are looking for 340°F to 350°F (170°C to 175°C) if you have a thermometer, but colour is a reliable guide here. At this shade the caramel will taste complex and slightly bitter, not just sweet. If it smells faintly smoky, pull it off immediately.
Do not walk away from the pan during the last 3 minutes. Caramel moves from amber to burnt in under a minute, and there is no recovering an over-cooked batch.
Step 3: Stir in the Butter and Baking Soda
Take the pan off the heat and add the 2 tbsp unsalted butter, 1/2 tsp fine sea salt, and 1/4 tsp baking soda. The mixture will bubble up vigorously, which is exactly what you want. Stir quickly with a heatproof spatula for about 15 seconds until the butter is fully melted and the foam starts to settle, then stir in the 1/2 tsp vanilla extract.
The caramel will lighten in colour and look slightly foamy. That is the baking soda doing its job, creating tiny air bubbles that make the final brittle crack cleanly instead of shattering into shards.
Work fast from here. Once the butter is in, the caramel starts to set up quickly.
Step 4: Fold in the Warm Nuts and Seeds
Tip the warm toasted nut and seed mixture into the caramel all at once. Using the spatula, fold everything together with about 6 to 8 turns, making sure every nut and seed is coated. You have roughly 30 to 40 seconds before the caramel gets too thick to move.
The mixture should look glossy and uniformly amber-coated. If a few sesame seeds settle at the bottom of the pan, that is fine; they will come out when you pour.
Step 5: Spread and Crack the Brittle
Immediately pour the mixture onto your prepared baking sheet. Working quickly, use the back of the spatula to spread it into a layer about 1/4 inch (6mm) thick. Do not press too hard; nudge the edges outward and let the caramel self-level as much as it can. Leave it undisturbed at room temperature for 20 to 25 minutes, until fully hardened and cool to the touch.
Once set, lift the whole slab and crack it into irregular pieces roughly 2 to 3 inches wide. Arrange them on a board or plate with the glossy caramel side facing up, where the light catches the amber color and the mix of seeds and nuts is visible through the brittle.
Recipe Tips
- Use a heavy-bottomed pan. A thin saucepan heats unevenly and makes it much harder to judge when the caramel has reached the right colour without hot spots burning part of it.
- Do not stir the caramel after adding honey. Stirring encourages crystallisation. Swirl the pan instead. If you see sugar crystals forming on the sides, brush them down with a wet pastry brush.
- Measure everything before you start the caramel. Once the sugar hits colour, there is no time to find a measuring spoon. Have the butter, baking soda, salt, vanilla, and nuts all sitting out and ready to go.
- Humidity affects the set. On a very humid day, brittle can stay slightly tacky. If that happens, lay the pieces on a parchment-lined sheet and put them in a 200°F (90°C) oven for 5 minutes, then cool again.
Cook time by caramel stage, starting from when the sugar fully dissolves:
| Caramel Stage | Colour | Approx. Time |
|---|---|---|
| Light gold | Pale yellow | 7 to 9 mins |
| Medium amber | Dark orange juice | 10 to 12 mins |
| Deep amber (target) | Mahogany brown | 13 to 14 mins |
| Burnt | Near black | 15+ mins, discard |
How To Store
- Refrigerate – not recommended; the moisture in a fridge makes brittle go soft and sticky within hours.
- Room temperature – layer the pieces between sheets of parchment in an airtight tin or container, and they will stay crisp for up to 10 days.
- Freeze – brittle freezes well for up to 2 months in a sealed zip bag with the air pressed out. Let it come to room temperature for 15 minutes before serving; condensation forms if you eat it straight from frozen.
Frequently Asked Questions
Can I make this without a silicone mat?
Yes. Lightly grease a sheet of parchment with a neutral oil, then lay it on the baking sheet. The brittle will release cleanly once cooled.
Why did my caramel crystallise and turn grainy?
Crystallisation usually happens because the mixture was stirred after the sugar dissolved, or because a few sugar crystals fell back into the pan from a spoon or the sides. Swirling instead of stirring, and brushing the sides with a wet brush, prevents it.
Can I double the batch?
You can, but use a larger saucepan and a second baking sheet. A double batch of caramel takes longer to reach colour and heats less evenly, so watch it closely from the 12-minute mark.
Can I skip the baking soda?
Technically yes, but the brittle will be glassier and harder to bite through. The baking soda creates a slightly lighter, more crackable texture, so it is worth including.
Costco Nut and Seed Brittle Recipe
Ingredients
Method
- Heat oven to 300°F (150°C). Spread almonds, cashews, pumpkin seeds, sunflower seeds, and sesame seeds on a dry baking sheet and toast for 8 minutes until the sesame seeds are pale gold. Set aside, keeping the nuts warm.
- Line a large baking sheet with a silicone mat or greased parchment. In a heavy-bottomed saucepan over medium heat, stir sugar and water together until dissolved, about 2 minutes. Add honey, stop stirring, and cook, swirling occasionally, for 10 to 14 minutes until the caramel turns deep amber (340°F to 350°F / 170°C to 175°C).
- Remove from heat and stir in butter, sea salt, and baking soda. The mixture will foam up. Stir for 15 seconds until butter melts and foam settles, then stir in vanilla extract.
- Add the warm nut and seed mixture all at once and fold together with 6 to 8 turns until everything is coated.
- Pour onto the prepared baking sheet and spread to roughly 1/4 inch (6mm) thick. Leave undisturbed for 20 to 25 minutes until fully set. Crack into pieces and arrange glossy-side up on a board to serve.
