Mustikkapiirakka

Prepare wheat flour, butter, sugar, eggs and sour cream for Mustikkapiirakka.

Mix the wet and dry components separately, then combine until smooth.

For creamy desserts, heat gently; for dough-based desserts, cook until set or browned.

Add sugar, sour cream, blueberries and butter at the right moment: into the mixture, filling, or for serving.

Let the dessert cool, set, or rest briefly.

Serve in portions.