Preheat your oven to roughly 350° F/ 160° C. Grease and dust whichever pan you're using for this.
Place 2 very ripe bananas in a small bowl and mash with a fork.
Now whisk together the 12 T - 170 gr of melted butter, 3/4 c - 165 gr of sour cream, 1 T - 18 gr of curry paste, 1/2 t - 2 gr of banana extract, 2 large eggs and 1 large egg yolk in a large bowl. Add the bananas and stir to combine.
Mix together 1 c - 200 gr of sugar, 1 c - 135 gr of all purpose and 1 c - 120 gr of cake flour with 1 1/2 tsp - 5 gr of baking powder, 1 tsp - 6 gr of baking soda and 1 1/4 tsp - 5 gr of salt in another large bowl. Pour the wet ingredients in with the dry and stir to combine. Use a whisk to break up any lumps.
Finally pour the combined batter into your greased and dusted cake pan. Bake the cake for 60 minutes or so, until the cake rises and puffs. Tap the top of your cake with your fingertips. If the cake bounces back firmly and the center is no longer jiggly, the cake should be done. If it does not pass this test, give it another 5 to 10 minutes and then try again.
Let the cake cool in the pan for at least 45 minutes, before turning it over onto a wire rack and allowing it to cool completely. While you try your patience you can make the black pepper butter.