1/2 cup plus 2 tbs unsalted butter, at room temperature
1 cup plus 6 tbs sugar
2 teas vanilla extract
3 large eggs, at room temperature
3 very ripe bananas, mashed
Preheat the oven to 325 degrees F. Line a muffin tin with paper liners.
Make the filling: Beat cream cheese and vanilla until smooth in the bowl of your stand mixer with the paddle attachment. About 2 minutes. Scrape out into a bowl. Clean the mixing bowl thoroughly. Using the whisk attachment, beat the egg whites on medium-high speed until frothy. Gradually beat in the sugar. Increase the speed to high and mix until shiny, stiff peaks form, about 3 minutes. Gently, add half of the cream cheese mixture in and meat until just combined. Add the remaining cream cheese and beat until smooth. Place filling in a pastry bag fitted with a large round tip; set aside.
Make the cakes: Mix together the flour, baking soda, and salt in a medium bowl.
Clean out the mixer again. Using the paddle attachment, beat the butter, sugar, and vanilla on medium speed until fluffy, about 5 minutes. Beat in the eggs, one at a time, scraping down the sides as needed. Beat in the mashed bananas until just combined. Carefully mix in half the flour mixture until just combined. Fold in the remaining flour until just combined being careful not to overmix.
Divide the batter among the prepared muffin tins. Insert the pastry tip halfway into each muffin and pipe 1 tbs of filling into the middle of the batter, filling each to about three quarters of the way full.
Bake until a toothpick inserted into the cake (not the filling) comes out clean, 20 to 35 minutes. Transfer the pan to a rack and let cool 15 minutes. Turn out the cakes to the rack to cool completely before serving.