Prepare a baking mold and line it with parchment paper, then lightly butter the sides. Preheat the oven.
2
Sift the cake flour and baking powder together to prevent lumps.
3
Peel the ripe bananas and mash them with a fork, leaving some small chunks for texture.
4
Beat the softened butter with a whisk until pale, then add sugar and mix until well combined.
5
Warm the egg to room temperature, then add it to the butter mixture in portions, stirring well after each addition to avoid curdling.
6
Fold the mashed banana into the mixture.
7
Switch to a spatula and gently fold in the sifted flour from the bottom up, being careful not to overmix to maintain a tender crumb.
8
Add nuts if desired, then pour the batter into the prepared mold, smooth the surface with a spatula, and tap the bottom gently to settle the batter.
9
Bake in the preheated oven until a toothpick inserted into the center comes out clean. If there is still batter on the toothpick, bake for another 5 minutes.
10
Remove the cake from the oven and let it cool. Cover with cheesecloth to prevent drying. Enjoy warm for a tender texture, or refrigerate for about 12 hours for a denser, more flavorful cake before slicing.