Line the wells of a muffin/cupcake pan with paper cupcake liners, or spray with baking spray. Preheat oven to 350 degrees F.
Dice the strawberries and place in a small bowl. Sprinkle with 2 tablespoons (15g) of the all-purpose flour and toss with a fork until the pieces of fruit are coated with flour. Set aside.
In a medium bowl, whisk together the remaining flour, baking powder and salt. Set aside.
In the bowl of an electric mixer, beat the sugar and butter until light and fluffy, about 3 minutes. Scrape down the sides of the bowl with a spatula as needed.
Add the egg and bakery emulsion (or vanilla extract), and beat 2 minutes more until fluffy.
Add the dry ingredients and sour cream alternately, 1/3 at a time. Blend until well combined. End with the flour mixture. Scrape down sides of bowl as needed.
Mix in the jam until well combined.
Fold in the diced strawberries with the flour, mixing by hand with a spatula until the strawberries are well distributed.
Divide the batter among 15-16 cupcake cups, filling each about 2/3 full. Do not overfill.
Bake at 350°F for 22-24 minutes, or until a toothpick inserted comes out clean. Let cool for 10 minutes before removing to a wire rack to cool completely.