In a saucepan, combine fresh or frozen blueberries, sugar, lemon juice, water, and a pinch of salt. Heat until thickened, about 5-7 minutes.

In another saucepan, melt unsalted butter over medium heat until golden brown, about 3-5 minutes. Allow to cool.

In a large bowl, cream cooled butter with granulated and brown sugars until fluffy. Add eggs and vanilla, mix until glossy.

In a separate bowl, whisk flour, baking powder, salt, and cinnamon. Combine with wet ingredients and fold in blueberries.

Portion dough into balls, create wells, and fill with blueberry jam. Chill for at least 30 minutes.

Combine brown sugar, flour, and cinnamon for the streusel. Cut in cold butter until crumbly.

Preheat oven to 350°F (175°C). Place dough on a baking sheet, top with streusel, and bake for 15 minutes.