Creating Lemon Stuffed Cupcakes is straightforward if you follow these step-by-step instructions:

1. Preheat the Oven: Begin by preheating your oven to 350°F (175°C). Line a cupcake pan with paper liners.

2. Make the Lemon Filling:
– In a medium saucepan, combine lemon juice, sugar, and eggs. Whisk until smooth.
– Add cornstarch and mix well. Cook over medium heat, stirring constantly until thickened, about 5-7 minutes.
– Remove from heat and stir in butter until melted. Let it cool while you prepare the cupcakes.

3. Mix Dry Ingredients: In a large mixing bowl, whisk together the flour, baking powder, and salt.

4. Cream Butter and Sugar: In another bowl, cream the softened butter and sugar together until light and fluffy.

5. Add Eggs and Vanilla: Beat in the eggs one at a time, followed by the vanilla extract and lemon zest.

6. Combine Mixtures: Gradually add the dry ingredients to the wet mixture, alternating with the milk. Mix until just combined.

7. Fill the Cupcake Liners: Spoon the batter into the lined cupcake pan, filling each cup about two-thirds full.

8. Bake: Place the pan in the preheated oven and bake for 20-25 minutes or until a toothpick inserted into the center comes out clean.

9. Cool the Cupcakes: Once baked, remove the cupcakes from the oven and let them cool in the pan for 5 minutes. Then transfer them to a wire rack to cool completely.

10. Stuff the Cupcakes: Once cooled, use a small knife or cupcake corer to remove a small section from the center of each cupcake. Fill the cavity with the cooled lemon filling.

11. Top (Optional): If desired, dust the cupcakes with powdered sugar or decorate with lemon zest for a beautiful finishing touch.

These steps will guide you in creating these incredible Lemon Stuffed Cupcakes that are sure to impress!