Preheat your oven to 350°F and line a 12-count muffin pan with cupcake liners.
In a medium bowl, whisk the flour, baking powder, baking soda, and salt, and set aside.
In a large bowl, use a hand-held mixer to beat the softened butter until smooth and creamy. Add the granulated sugar and beat with the butter until well combined, light, and fluffy. Mix in the room temperature eggs, one at a time, until just combined after each. Scrape the sides of the bowl with a rubber spatula as needed. Add the strawberry extract, full-fat sour cream, whole milk, and ¼ cup strawberry sauce and mix until smooth. Add the dry ingredients and mix until combined and smooth.
Scoop the batter evenly into the cupcake liners, filling each ⅔ of the way full. Bake for 16-17 minutes. A toothpick inserted in the center should come out clean. Allow the cupcakes to cool slightly in the pan, then cool completely in the fridge before frosting.