Ingredients

2 1/2 cups (354g) all-purpose flour
1 1/2 tsp baking powder
1/2 tsp salt
1 cup (210g) granulated sugar
1 Tbsp lemon zest
10 Tbsp (5 Oz) unsalted butter, softened partially
1 large egg
1 large egg white
2 Tbsp sour cream
1 tsp lemon extract
1 tsp vanilla extract
Frosting
1/2 cup (4 Oz) unsalted butter, softened
2 1/2 cups (297g) powdered sugar
2 tsp lemon zest
2 Tbsp fresh lemon juice
Yellow food coloring and sprinkles (optional)