Step 1: Preheat and Prepare

Preheat your oven to 350°F (175°C). Line a muffin tin with 12 cupcake liners to prevent sticking and make cleanup easier.

Step 2: Mix Dry Ingredients

In a medium bowl, whisk together flour, baking powder, and salt. Mixing these dry ingredients first helps ensure even distribution, preventing pockets of baking powder or salt in the batter.

Step 3: Cream Butter and Sugar

In a large bowl, use an electric mixer to beat butter and sugar together until the mixture is light and fluffy. This process, called creaming, incorporates air into the batter, making the cupcakes soft and tender.

Step 4: Add Eggs and Vanilla

Add eggs one at a time, beating well after each addition. Stir in vanilla extract to enhance the flavor. Scrape down the sides of the bowl to ensure everything is well combined.

Step 5: Combine Wet and Dry Ingredients

Gradually add the dry ingredients to the butter mixture, alternating with milk. Begin and end with the dry ingredients, mixing until just combined. Overmixing at this stage can lead to dense cupcakes.

Step 6: Fold in Blueberries and White Chocolate

Gently fold in blueberries and white chocolate chips using a spatula. To prevent blueberries from sinking to the bottom of the cupcakes, lightly coat them in flour before adding them to the batter.

Step 7: Bake

Spoon the batter into cupcake liners, filling each about two-thirds full. Bake for 18-20 minutes, or until a toothpick inserted in the center comes out clean. Let the cupcakes cool in the pan for five minutes before transferring them to a wire rack to cool completely.

Step 8: Make the Frosting

In a bowl, beat butter and powdered sugar until smooth. Add vanilla extract and heavy cream, then mix until fluffy. Finally, stir in melted and cooled white chocolate. The frosting should be thick but spreadable. If too stiff, add a little more cream; if too soft, chill briefly before using.

Step 9: Decorate

Once the cupcakes are completely cool, frost them using a piping bag or a spatula. For extra decoration, top with additional blueberries and white chocolate chips.