For the Raspberry Cupcakes

1. Preheat your oven to 350 degrees Fahrenheit. Line a 12-count muffin tin with liners or grease heavily to ensure the cupcakes come out of the tin cleanly.
2. In a large bowl, use a whisk to combine granulated sugar, room temperature egg, vanilla extract, and room temperature buttermilk together until smooth.
3. Add properly-measured all purpose flour, baking powder, baking soda, and salt into the batter and whisk only until you see the dry ingredients disappear into the batter. Mixing past when the ingredients are combined could create dense cupcakes.
4. Coat the raspberries in the flour to ensure they do not sink to the bottom of the cupcakes and to help prevent the juice from bleeding. Carefully, use a spatula to fold the raspberries into the batter to avoid breaking them and causing the fruit to bleed into the batter.
5. Divide the batter between the 12 liners, adding about 1/4 cup of batter to each liner until it reaches 2/3 full.
6. Bake the cupcakes for 18-22 minutes or until the tops are light golden brown, domed, and a toothpick inserted into the center comes out with a few moist crumbs. Allow the cupcakes to fully cool before frosting.

For the Raspberry Buttercream

1. In a large bowl with a hand mixer or in the bowl of a stand mixer, beat the room temperature butter and powdered sugar together on medium speed until smooth.
2. Add the raspberries to the frosting and beat on high speed until combined. Use a spatula to scrape down the sides and the bottom of the bowl to ensure the raspberries are dispersed throughout.
3. Pour milk into the frosting and beat on medium speed for about 2 minutes. This should smooth out the frosting.
4. If desired, transfer the frosting to a piping bag or zippable bag with the corner cut off. Frost the cupcakes as desired.
5. Store the cupcakes in an airtight container or tightly covered at room temperature for up to 3 days or in the freezer for up to 3 months.