In a large bowl, whisk together 3 cups all-purpose flour, 1.5 cups granulated sugar, 2 tsp baking powder, 1/2 tsp baking soda, and 1 tsp salt until evenly distributed.

Cream butter and mix wet

In a separate bowl, cream 1/2 cup softened unsalted butter with 1/4 cup vegetable oil until smooth. Add 3 large eggs one at a time, mixing until incorporated. Stir in 1 cup whole milk and 2 tsp vanilla extract.

Combine wet and dry

Add the wet mixture to the dry ingredients and stir until just combined; do not overmix. The batter should be thick but pourable. If making red velvet, reserve step to add cocoa, food coloring, and vinegar at this stage and use buttermilk instead of whole milk per the Red Velvet section. If making carrot cupcakes, fold in grated carrots and chopped nuts here as directed in the Carrot Cake section.

Fill and bake

Spoon batter into prepared liners, filling each about 3/4 full for oversized cupcakes. Bake in the preheated oven for 20–26 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs (time may vary with oversize liners; check at 18 minutes). Rotate pan halfway through if your oven has hot spots.

Cool

Allow cupcakes to cool in the pan for 10 minutes, then transfer to a wire rack to cool completely before topping or slicing for filling.

Chocolate Mousse Topping

Chop 8 oz semisweet chocolate and place in a heatproof bowl. Heat 1 cup heavy cream in a small saucepan until it just begins to simmer, then pour over the chocolate. Let sit 1 minute, then gently stir until smooth. Add 1 tbsp room-temperature butter and 2 tbsp powdered sugar; stir to combine. Chill the mixture until thick but pipeable (about 30–45 minutes). Whip slightly with a hand mixer to lighten if necessary, then pipe or spoon on cooled cupcakes.

Strawberry Shortcake Topping & Filling

Toss 4 cups hulled and quartered strawberries with 1/4 cup granulated sugar and 1 tsp lemon juice. Let macerate at room temperature 20–30 minutes until juicy. Spoon a tablespoon of macerated strawberries over each cooled cupcake or cut a shallow well in the center and fill with berries. Top with 2 cups whipped cream (stabilized if holding longer) and an extra strawberry for garnish.

Carrot Cake Add-ins & Cream Cheese Frosting

When making the base batter for carrot cupcakes, fold in 2 cups finely grated carrots and 3/4 cup chopped nuts to the combined batter just until evenly distributed before filling tins (see Base Cupcake Batter step for bake time).

For the cream cheese frosting: Beat 8 oz softened cream cheese with 4 tbsp softened unsalted butter until smooth. Gradually add 1.5 cups powdered sugar and 1 tsp vanilla, beat until fluffy. Frost cooled carrot cupcakes with a generous swirl and sprinkle with reserved chopped nuts.

Red Velvet Additions & Frosting

To make red velvet from the base batter: reduce milk to 1 cup buttermilk, whisk in 1 tbsp unsweetened cocoa powder, 2 tbsp red food coloring, and 1 tsp white vinegar into the wet ingredients before combining with dry. Proceed with combining and baking as in Base Cupcake Batter. This yields the characteristic red color and mild cocoa flavor.

For the cream cheese frosting: Beat 8 oz softened cream cheese with 4 tbsp softened unsalted butter until smooth. Gradually add 1.5 cups powdered sugar and 1 tsp vanilla, beating until light and spreadable. Frost cooled red velvet cupcakes as desired.