Start by melting butter over medium heat until it turns golden brown and smells nutty. Stir continuously to avoid burning and remove from heat once browned. Let it cool slightly before using so it doesn’t cook the eggs.

In a bowl, whisk together the brown butter, brown sugar, and granulated sugar until smooth. Add eggs, mashed bananas, Greek yogurt, and vanilla extract. Mix until everything is well combined and creamy.

In another bowl, combine flour, baking soda, salt, and cinnamon. This ensures even distribution and prevents lumps. Gradually fold the dry ingredients into the wet mixture without overmixing.

Gently mix until just combined to keep the cake light and fluffy. Overmixing can make the cake dense, so stop once no flour streaks remain. Pour the batter into a greased baking pan.

Bake the cake base until it is mostly set but still slightly soft in the center. This step helps support the topping later. Use a toothpick to check—it should come out with a few moist crumbs.

Spread the almond frangipane mixture over the partially baked cake. Sprinkle sliced almonds evenly on top. This layer adds richness and gives that signature almond croissant texture.

Return the cake to the oven and bake until fully cooked. For extra crunch, lightly toast or broil the almonds for 1–2 minutes. Keep a close eye to avoid burning.

Let the cake cool completely before adding glaze. Drizzle a simple vanilla glaze over the top and dust with powdered sugar. This final touch gives it a bakery-style finish.