Preheat your oven to 350°F (175°C). Prepare one 8-inch round cake pan by greasing it with nonstick baking spray and lining it with parchment paper.
In a medium mixing bowl, whisk together 2 1/2 cups of cake flour, 3/4 teaspoon of baking powder, 1/4 teaspoon of baking soda, and 3/4 teaspoon of salt.
In the bowl of a stand mixer, whisk together 3/4 cup of melted butter, 1 1/2 cups of ultrafine baking sugar, 1 1/2 eggs (whisk two eggs together and use half), 6 tablespoons of vanilla Greek yogurt, 1 1/8 cups of milk, and 3 teaspoons of vanilla extract until well combined.
Slowly add the dry ingredients to the wet ingredients, scraping down the sides as needed, and mix until no lumps remain.
Pour the batter into the prepared cake pan and bake for 25-30 minutes or until a toothpick inserted into the center comes out clean. Remove from the oven and let cool on a wire rack for 10 minutes, then refrigerate until fully cooled.
For the frosting, beat 3/8 cup of softened unsalted butter until fluffy. Gradually add 1 1/2 to 2 cups of sifted powdered sugar and beat for an additional minute. Add 1 1/2 to 2 1/2 tablespoons of heavy cream, 1/2 teaspoon of vanilla extract, and a pinch of salt, and beat on high for 2 minutes. Add more cream if needed to achieve the desired consistency.
To assemble the cake, level the cake and slice it in half horizontally. Spread a layer of frosting over the bottom half of the cake, then top with sliced strawberries and banana. Place the top half of the cake over the filling.
Use the remaining frosting to frost the top and sides of the cake. Press mini chocolate chips onto the sides of the cake and decorate the top with additional frosting, strawberries, and banana slices.