Preheat your oven to 350°F (175°C) and grease two 9-inch round cake pans with butter or non-stick spray. Dust them lightly with flour.

In a large mixing bowl, combine the flour, sugar, salt, baking powder, and baking soda.

Add the softened butter and mix until the mixture resembles coarse crumbs.

In a separate bowl, whisk together the eggs, whole milk, Greek yogurt, lemon zest, and lemon juice until smooth.

Pour the wet mixture into the dry ingredients, stirring just until combined.

Gently fold in the blueberries until evenly distributed.

Divide the batter equally between the prepared cake pans and tap them lightly on the countertop to eliminate air bubbles.

Bake in the preheated oven for about 25-30 minutes, until a toothpick inserted in the center comes out clean.

Let the cakes cool in the pans for about 10 minutes before transferring them to wire racks to cool completely.

In a bowl, beat the softened butter until creamy.

Gradually add the powdered sugar, mixing well after each addition.

Add vanilla extract, lemon juice, and a pinch of salt. Beat until fluffy and smooth.