Preheat oven to 350℉ (180℃) and line a 12-capacity cupcake pan with paper liners.
In a medium bowl, hand whisk together the flour, baking powder, baking soda, and salt to combine.
188 grams all purpose flour, 1 teaspoon baking powder, ½ teaspoon baking soda, ¼ teaspoon fine sea salt or kosher salt
Using a separate large bowl with an electric hand mixer on medium speed, cream together the sugar and softened butter. About 2 minutes. Beat in the eggs one at a time, followed by the mashed bananas and vanilla.
Reduce speed to low and mix in half of the flour mixture, then the crème fraiche. Lastly mix in the remaining flour mixture to form a light airy batter. Use a rubber spatula to scrape the sides and bottom of bowl as needed.
80 grams crème fraiche
Divide the batter evenly amongst the cupcake liners, measure about 3 tablespoons of batter into each cupcake liner. Each liner should be ¾ of the full of batter.
Transfer the cupcake pan to center of the medium rack in the oven. Bake the cupcakes for 18-20 minutes or until a toothpick inserted into the center comes out clean.
Place the cupcake pan on a wire cooling rack to cool for 10 minutes.
Then, carefully remove each cupcake and place them directly on a wire rack to cool completely before frosting.
Chocolate Buttercream Frosting
Scoop the buttercream into a plastic pastry piping bag with a star piping tip and pipe frosting onto the cupcakes.
1 batch Chocolate Buttercream Frosting
Notes
Store cupcakes in an air tight container at room temp for 3-5 days.