3 cups all-purpose flour
1 tbsp baking powder
1/2 teaspoon salt
1 cup unsalted butter, room temperature
2 cups sugar
4 large eggs,
3 tbsp finely grated lemon zest
2 tbsp lemon juice
1 tsp pure vanilla extract
1 cup buttermilk
Preheat oven to 325 degrees and line standard muffin tins. Whisk together flour, baking powder, and salt.
On medium-high speed, cream butter and sugar until pale and fluffy. Add eggs, one at a time, beating until each is incorporated, scraping down sides of bowl as needed. Beat in zest and vanilla. Add flour mixture in three batches, alternating with two additions of buttermilk and lemon juice, and beating until just combined after each.
Divide batter evenly among lined cups, filling each 3/4 full. Bake until golden brown, about 25 minutes.
Vanilla - Lemon Cream Filling
3 tbsp flour
1/2 c milk
1/2 c (1 stick) butter, room temperature
1/2 c granulated sugar
1 tsp. vanilla
1/8 tsp. salt
1 tsp fresh lemon juice
Whisk together the flour and milk in a small saucepan. Place over medium heat. Whisk continuously until it begins to thicken. Let it cook for a couple of minutes, until the mixture has the consistency of pudding. Remove from heat, whisk out all clumps, and place in refrigerator to cool completely. The mixture must be chilled all of the way thorough before adding it to the butter, or it will melt it.
In the bowl of a stand mixer, beat the butter, sugar, vanilla, lemon juice and salt for 2 minutes on medium-high speed, using the whisk attachment. Add flour and milk mixture. Beat on high for 6-8 minutes until the mixture is light and fluffy (and slightly resembles whipped cream). Chill in refrigerator.
3 sticks unsalted, room temp butter
3 1/2 - 4 cups confectionery sugar
1 tsp vanilla extract
1 tbsp fresh lemon juice
Begin whipping butter in a stand mixer until fluffy, about 3-4 minutes. Gradually add in sugar until desired consistency is met for piping. Add vanilla and juice, mix again until incorporated. Top with fresh zest or sprinkles.