Preheat your oven to 335°F (168°C) and prepare three 7-inch round cake pans.

In a stand mixer, cream together unsalted butter and granulated sugar until light and fluffy, about 3-5 minutes.

In a separate bowl, whisk together cake flour, baking powder, and salt.

Combine the buttermilk mixture with the dry ingredients and mix until just combined.

Gently fold in fresh blueberries.

Divide the batter among the pans and bake for 35-40 minutes.

Let the cakes cool for 15 minutes before inverting them onto a wire rack.

While cooling, beat together the frosting ingredients until smooth and creamy.

Once the cakes are cool, assemble with frosting in between the layers and coat the outside.

Decorate as desired and serve.