Step-by-Step Instructions

1. Preheat the Oven:
   • Preheat your oven to 350°F (175°C). Line a muffin tin with cupcake liners.
2. Prepare the Lemon Cupcakes:
   • In a medium mixing bowl, whisk together the flour, baking powder, baking soda, and salt.
   • In a large mixing bowl, beat the butter and sugar together until light and fluffy. Add the eggs one at a time, beating well after each addition.
   • Mix in the sour cream, lemon juice, and lemon zest until combined.
   • Gradually add the dry ingredients to the wet ingredients, alternating with the milk, beginning and ending with the dry ingredients. Mix just until combined.
   • Divide the batter evenly among the cupcake liners, filling each about two-thirds full.
3. Bake the Cupcakes:
   • Bake in the preheated oven for 20-25 minutes, or until a toothpick inserted into the center comes out clean. Allow the cupcakes to cool in the tin for 5 minutes, then transfer them to a cooling rack to cool completely.
4. Prepare the Raspberry Filling:
   • In a small saucepan, combine the raspberries, sugar, and lemon juice. Cook over medium heat until the raspberries break down and the mixture begins to simmer.
   • Stir in the cornstarch mixture and cook for another 1-2 minutes, until the filling thickens. Remove from heat and let cool completely.
5. Prepare the Lemon Cream Cheese Frosting:
   • In a large mixing bowl, beat the cream cheese and butter together until smooth and creamy.
   • Gradually add the powdered sugar, beating until fully incorporated and smooth. Mix in the lemon zest, lemon juice, and vanilla extract until combined.
6. Assemble the Cupcakes:
   • Once the cupcakes are completely cool, use a small knife or cupcake corer to remove a small portion from the center of each cupcake.
   • Fill each cupcake with a spoonful of the raspberry filling.
   • Pipe the lemon cream cheese frosting on top of each cupcake using a piping bag and your preferred tip.