• Set the diced strawberries, for the filling, onto a paper towel to dry out while making the rest of the recipe.
  10 medium strawberries

Vanilla Cupcake

• Preheat the oven to 350F/177C convection (325F/163C conventional) and line 13 muffin tins with cupcake liners (preferably a light colored pan).
• In a medium bowl, whisk together the cake flour, baking soda, baking powder, salt and sugar. Add the oil and butter to the dry ingredients and beat together until they're combined. Add the egg whites and vanilla extract and mix until they're fully combined. Then add the milk and sour cream, mixing just until the batter is smooth. 
  1 1/2 cup (172g) cake flour, 1/4 tsp baking soda, 1/2 tsp baking powder, 1/4 tsp salt, 1 cup (200g) granulated sugar, 1/4 cup (59mL) canola oil, 1/4 cup (56g) unsalted butter, 2 large, 2 tsp vanilla extract, 1/3 cup (78mL) whole milk, 1/2 cup (113g) sour cream
• Fill each cupcake liner about 2/3-3/4 full (about 50g). Bake for 16-18 minutes. The cupcake should no longer look wet and when you press on the center of the cupcake it should spring back, or once a toothpick inserted comes out clean.
• Remove them from the oven and let them cool in the cupcake pan for 10 minutes, then move them to a cooling rack. Allow the cupcakes to cool completely and then use a cupcake corer or a knife to cut a whole out the center. Set aside.

Cream Cheese Frosting

• In the bowl of a stand mixer, cream together the butter, cream cheese and vanilla for 1-2 minutes, until they're smooth and creamy. Add in the powdered sugar and salt and turn the mixer to low speed.
  1/2 cup (113g) unsalted butter, 1/2 cup (112g) cream cheese, 2 tsp vanilla bean paste, 3 1/2 cups (420g) powdered sugar, 1/8 tsp salt
• Once the sugar is combined, turn the mixer up to medium-high speed and beat until the sugar is fully dissolved and the frosting feels smooth, about 5 minutes.
• Remove about 1/4 of the cream cheese frosting and set it aside for the filling. Add the strawberry jam to the rest of the frosting and mix until it's fully combined.* Refrigerate the frosting for 20-30 minutes while you do the filling.
  1/4 cup strawberry jam

Strawberry Cream Filling

• Fold together the reserved cream cheese frosting with the diced strawberries. Use a small spoon to fill the cupcakes. Remove the frosting from the fridge, mix it one more time so it's smooth. Use a piping bag to frost the cupcakes. Top with extra strawberries or clear sprinkles.
  1/4 of cream cheese frosting