Mustikkapiirakka with coffee or as an afternoon treat. This gluten-free version retains all the characteristic sweetness and tartness of this Nordic tart.
To prepare the dough: In a bowl, combine the rice flour, almond flour, salt, and sugar. Cut in the cold butter and work it in with your fingertips until the mixture resembles coarse sand. Add the egg and mix until a ball of dough forms. If the dough is too dry, you can add a teaspoon of cold water. You can also use a stand mixer. Refrigerate for 30 minutes.
Roll out the dough: Preheat the oven to 180°C (350°F). Roll out the dough in a tart pan, pressing it firmly into the edges. I roll out the dough between two sheets of cling film for easier handling. Prick the base lightly with a fork.