1. Prepare the Cupcake Batter: Creating a Light and Fluffy Base

1. Preheat Oven and Line Muffin Tin: Preheat your oven to 350°F (175°C). Line a 12-cup muffin tin with cupcake liners.
2. Whisk Dry Ingredients: In a medium bowl, whisk together the flour, baking powder, and salt. Set aside.
3. Cream Butter and Sugar: In a large bowl, using an electric mixer, cream together the softened butter and granulated sugar until the mixture is light and fluffy, about 2-3 minutes.
4. Add Eggs and Vanilla: Beat in the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.
5. Gradually Add Dry Ingredients: With the mixer on low speed, gradually add the dry ingredients to the wet ingredients, alternating with the milk, beginning and ending with the dry ingredients. Mix until just combined. Be careful not to overmix.
   • Example: Add about ⅓ of the dry ingredients, mix, then add ½ of the milk, mix, and repeat, ending with the final ⅓ of the dry ingredients.

    

2. Prepare the Raspberry Swirl: A Sweet and Tangy Addition

1. Puree Raspberries: In a blender or food processor, combine the fresh raspberries and 2 tablespoons of granulated sugar. Blend until smooth.
2. Strain (Optional): If you prefer a seedless puree, strain the mixture through a fine-mesh sieve, pressing on the solids with the back of a spoon to extract as much puree as possible. Discard the seeds.

3. Assemble the Cupcakes: Creating the Beautiful Swirl

1. Fill Liners: Fill each cupcake liner with batter until it’s about halfway full.
2. Add Puree: Drop a small spoonful (about ½-1 teaspoon) of the raspberry puree onto the center of the batter in each liner.
3. Swirl: Using a toothpick or a knife, gently swirl the raspberry puree into the batter, creating a marbled effect.
   • Tip: Don’t over-swirl, or the colors will become muddy. Aim for a few distinct swirls.

4. Bake the Cupcakes: Achieving Golden-Brown Perfection

1. Bake: Bake in the preheated oven for 18-20 minutes.
2. Check for Doneness: The cupcakes are done when a toothpick inserted into the center comes out clean, or with just a few moist crumbs attached. The tops should be lightly golden brown.
3. Cool: Remove the muffin tin from the oven and let the cupcakes cool in the tin for about 10 minutes before transferring them to a wire rack to cool completely.

5. Prepare the Swirl Frosting: A Two-Toned Delight

1. Beat Butter: In a large bowl, beat the softened butter with an electric mixer until it’s light and creamy.
2. Gradually Add Powdered Sugar: Gradually add the powdered sugar, one cup at a time, beating on low speed until it’s fully incorporated and the frosting is smooth.
3. Add Vanilla: Beat in the vanilla extract.
4. Divide Frosting: Divide the frosting into two equal portions in separate bowls.
5. Flavor and Color One Portion: To one portion of the frosting, add 2 tablespoons of the strained raspberry puree and mix until well combined. If desired, add a few drops of natural red food coloring to enhance the pink color, and mix until you achieve your desired shade.
   • Tip: Add the food coloring gradually, as a little goes a long way.
6. Leave Other Portion White: Leave the other portion of the frosting white/uncolored.

6. Frost the Cupcakes: Creating the Swirl Effect

1. Prepare Piping Bag: Fit a large piping bag with a large star tip (or any tip you prefer).
2. Fill Piping Bag: Carefully place the two colors of frosting side by side in the prepared piping bag. Try to keep the colors separate as you fill the bag.
   • Tip: You can use a spoon or spatula to fill the bag, or you can stand the piping bag upright in a tall glass to make it easier to fill.
3. Pipe Frosting: Gently squeeze the piping bag to pipe the frosting onto the cooled cupcakes, creating a swirl pattern as the two colors blend together.
   • Tip: Practice piping on a piece of parchment paper first to get a feel for the technique.

7. Serve and Enjoy: Sharing the Sweetness

1. Serve: Serve the Raspberry Swirl Cupcakes immediately, or store them in an airtight container in the refrigerator.