01 -
In a pot, combine blueberries, sugar, lemon juice, vanilla, and cornstarch. Cook on medium-low heat for 30-40 minutes until thick. Let cool.
02 -
Whisk together flour, baking powder, and salt. Set aside.
03 -
Beat softened butter and granulated sugar until fluffy, about 2 minutes. Add egg and vanilla, mixing until pale and fluffy.
04 -
Slowly add dry ingredients to the butter mixture. Mix until dough comes together.
05 -
Gently mix cooled blueberry jam into the dough.
06 -
Scoop dough into 2 tbsp balls. Place on parchment-lined sheet and sprinkle with sugar.
07 -
Bake at 350°F (175°C) for 10-13 minutes until edges are golden. Let cool on the baking sheet for 5 minutes, then transfer to a cooling rack.