Whisk the dry ingredients together in a large bowl. Whisk the buttermilk, egg, melted butter, and vanilla in a separate bowl, then pour into the dry ingredients and stir until just combined, about 10 to 15 strokes. Rest the batter for 5 minutes.

Melt the butter for the caramel in a small saucepan over medium heat. Add the brown sugar and stir for 2 minutes until dissolved, then add the heavy cream and salt and stir for 1 to 2 minutes until glossy. Remove from heat.

Heat a lightly oiled non-stick skillet over medium heat. Pour 1/4 cup batter per pancake and cook 2 to 3 minutes until bubbles form and edges look set, then flip and cook 1 to 2 minutes more. Keep warm and repeat with remaining batter.

In the same pan over medium-low heat, warm the banana slices for about 1 minute per side until lightly golden at the edges.

Stack 3 pancakes per plate, layer bananas over and between them, then drizzle the caramel sauce over the top so it runs down the sides of the stack.