Creating these delightful Chocolate Strawberry Cupcakes with Chocolate Filling is simple if you follow these steps:

1. Preheat the Oven: Preheat your oven to 350°F (175°C). Line a cupcake tin with paper liners.
2. Mix Dry Ingredients: In a large bowl, sift together the flour, sugar, cocoa powder, baking powder, baking soda, and salt.
3. Combine Wet Ingredients: In another bowl, whisk the eggs, milk, vegetable oil, and vanilla extract until well combined.
4. Incorporate Dry and Wet Ingredients: Gradually add the wet ingredients to the dry ingredients, mixing until just combined. Be careful not to overmix.
5. Add Boiling Water: Stir in the boiling water carefully. The batter will be thin, but this will result in moist cupcakes.
6. Fill Cupcake Liners: Pour the batter into the lined cupcake tin, filling each liner about two-thirds full.
7. Bake: Bake in the preheated oven for 20-25 minutes or until a toothpick inserted in the center comes out clean. Let them cool for 15-20 minutes in the tin before transferring them to a wire rack.
8. Prepare Chocolate Filling: In a small saucepan over low heat, combine the semi-sweet chocolate chips and heavy cream. Stir until melted and smooth. Allow to cool slightly.
9. Fill Cupcakes: Once the cupcakes are cool, use a small knife or cupcake corer to remove a portion of the center. Fill each cupcake with the chocolate filling.
10. Make Strawberry Frosting: In a large mixing bowl, beat the softened butter until creamy. Gradually add powdered sugar, strawberry puree, vanilla extract, and a pinch of salt. Beat until light and fluffy.
11. Frost the Cupcakes: Using a piping bag or a spatula, frost the filled cupcakes with the strawberry frosting.