Birthday Cake Recipe

Prepare and preheat

Preheat oven to 350°F (175°C). Line a 12-cup muffin tin with paper liners or lightly grease. Bring eggs, milk, sour cream, and butter to room temperature before beginning for even mixing.

Dry ingredients

In a medium bowl, whisk together 2 cups all-purpose flour, 1.5 cups granulated sugar, 2 tsp baking powder, and 1/2 tsp sea salt until evenly combined. Set aside.

Cream butter and sugar

In a large mixing bowl using a hand mixer or stand mixer fitted with a paddle, beat 1/2 cup room-temperature unsalted butter on medium speed for about 1 minute until softened. Add the dry mixture? No — add 1.5 cups granulated sugar to the butter and cream together on medium-high for 2–3 minutes until pale and fluffy, scraping the bowl once.

Add eggs and vanilla

Add eggs one at a time, beating 20–30 seconds after each addition until incorporated. Add 2 tsp pure vanilla extract and mix to combine.

Alternate dry and wet

With the mixer on low, add the flour mixture in three additions alternating with 3/4 cup milk and 1/4 cup sour cream: begin with one third of the flour mixture, then half of the milk mixture (milk + sour cream combined), then second third of flour, the rest of the milk mixture, then the final third of flour. Mix only until just combined after each addition to avoid overmixing. Scrape the bowl to incorporate any streaks.

Fill tins

Spoon batter into the prepared muffin tin, filling each liner about 2/3 full (roughly 2.5 to 3 tablespoons batter per cupcake if making 12). Gently tap the pan once on the counter to settle the batter and release air bubbles.

Bake and cool

Bake for 17–20 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs. Rotate pan halfway through baking if your oven runs unevenly. Remove from oven and let cupcakes cool in the tin for 5 minutes, then transfer to a wire rack to cool completely (at least 30 minutes) before frosting.

Prepare fruit: If using fresh berries, lightly toss 1 cup berries with 1 tablespoon lemon zest and 1 tablespoon light brown sugar (optional) in a bowl. For chopped stone fruit, cut into small pieces and toss the same way. If you prefer a warm fruit accent, heat a small skillet over medium heat, add the fruit and brown sugar, and cook for 2–3 minutes until just softened and syrupy; cool to room temperature before using.

Add to cupcakes: Once cupcakes are cooled, you can either fold a teaspoon of the fruit mixture into the center by coring the cupcake with a paring knife and spooning in fruit, or place the fruit on top of the frosted cupcake as a garnish.

Beat butter

In a large bowl using a stand mixer or hand mixer, beat 1.5 cups softened unsalted butter on medium speed for 1–2 minutes until creamy and pale.

Add powdered sugar

Reduce speed to low and add 4 cups sifted confectioners' sugar, 1 cup at a time, mixing after each addition to avoid a sugar cloud. Once incorporated, increase speed to medium and beat for 30–45 seconds.

Flavor and thin

Add 2 tsp vanilla extract, 3 tbsp heavy cream (or milk), and 1/4 tsp fine sea salt. Beat on medium-high for 1–2 minutes until light and fluffy. If the frosting is too thick, add additional cream 1 tsp at a time until you reach piping consistency; if too thin, add 2–4 tbsp more powdered sugar.

Color (optional)

If desired, divide frosting into bowls and add a drop or two of gel food coloring to achieve summer or fall tones (soft peach, pale yellow, or muted auburn). Mix until color is even.

Pipe or spread

Fit a piping bag with your preferred tip or use an offset spatula. Pipe frosting onto cooled cupcakes in a swirl or spread with a spatula. Work quickly if using fresh fruit topping to avoid softening them.

Decorate each frosted cupcake with a teaspoon of prepared fruit or a few fresh berries. Sprinkle with 1/4 cup total sprinkles across the batch as desired. Top some cupcakes with small edible flowers or a fresh mint leaf for a summery/fall accent.

Storage and serving: Store frosted cupcakes in an airtight container at room temperature for up to 24 hours. If using fresh fruit or cream-heavy fillings, refrigerate and consume within 2 days. Bring refrigerated cupcakes to room temperature before serving for best texture (about 30 minutes).