Creating Chocolate Strawberry Cupcakes requires a few simple steps:

1. Preheat the Oven: Preheat your oven to 350°F (175°C) and line a muffin pan with cupcake liners.
2. Mix Dry Ingredients: In a large bowl, whisk together the flour, sugar, cocoa powder, baking soda, baking powder, and salt.
3. Combine Wet Ingredients: In another bowl, beat together the egg, milk, vegetable oil, and vanilla extract until well combined.
4. Combine Mixtures: Gradually add the wet ingredients to the dry ingredients, stirring until just combined.
5. Add Boiling Water: Carefully stir in the boiling water until the batter is smooth. The batter will be thin.
6. Fill Cupcake Liners: Pour the batter into the prepared cupcake liners, filling each about two-thirds full.
7. Bake: Place in the preheated oven and bake for 18-20 minutes, or until a toothpick inserted into the center comes out clean.
8. Cool: Remove from the oven and allow the cupcakes to cool in the pan for 5 minutes. Then, transfer them to a wire rack to cool completely.
9. Prepare the Frosting: In a large bowl, beat the softened butter until creamy. Gradually add the powdered sugar, strawberry puree, vanilla extract, and salt, mixing until smooth and fluffy.
10. Frost the Cupcakes: Once the cupcakes are completely cooled, frost them generously with the strawberry frosting using a piping bag or spatula.

By following these steps, you will create a batch of Chocolate Strawberry Cupcakes that are sure to impress your family and friends!