Preheat oven to 350F and grease two 8-inch round pans.

Cream 1 cup butter and 1.5 cups granulated sugar until light and fluffy.

Beat in 4 eggs one at a time, then stir in 2 tbsp zest and 0.25 cup juice.

Whisk 2.5 cups flour, 2 tsp baking powder, and 0.5 tsp salt. Alternate adding dry mixture and 1 cup buttermilk to the butter mixture.

Divide batter evenly between pans and bake for 30 minutes. Let cool completely.

For frosting, beat 1 cup butter, 4 cups powdered sugar, and 1 tsp extract until smooth.

Layer the cooled bake, cover with frosting, and add piped decorations.