Strawberry Filling

1. Combine all the ingredients in a small saucepan over medium heat. Stir to combine and cook until it begins to bubble. Allow to cook 1 minute, then remove from the heat.
2. Transfer to a heat-safe bowl to cool.

Strawberry Cupcakes

1. Preheat oven to 350°F/177°C. Line a muffin pan with cupcake liners. Set aside.
2. In a medium bowl, sift the flour, baking powder, baking soda, and salt.
3. In a large bowl, using a handheld or stand mixer fitted with the paddle attachment, beat the butter and sugar on medium-high speed until light and fluffy, 1-2 minutes. Scrape down the sides of the bowl as needed.
4. With the mixer running on medium-low speed, slowly stream in the oil and mix to combine.
5. Beat in the eggs, one at a time, until combined. Scrape down the sides of the bowl and beat in vanilla.
6. Add the sour cream and mix until completely combined.
7. With the mixer on low speed, add the dry ingredients and the milk. Beat until just combined. Gently fold in the strawberry puree.
8. Fill the cupcake liners 2/3 full and bake for 17-19 minutes, or until a toothpick inserted in the center comes out clean.
9. Allow the cupcakes to cool completely in the pans set on a wire rack before filling and frosting.

Strawberry Cream Cheese Frosting

1. In a large bowl, using a hand-held mixer or stand mixer fitted with the paddle attachment, beat the cream cheese and butter together on medium-high speed until smooth and creamy, 2-3 minutes.
2. Add the powdered sugar and mix on low speed until completely incorporated.  Add the strawberry reduction and vanilla and combine. Increase to medium-high speed and beat for 2 minutes.

Assemble Cupcakes

1. Using a paring knife or corer, hollow out the centers of the cupcakes without cutting through the bottoms.
2. Spoon or pipe the filling into each cupcake filling to the top of the cupcake.
3. Using a piping bag fitted with a large star tip or an offset spatula, frost the cupcakes to completely cover the filling.