• Preheat the oven to 375˚F degrees. Lightly butter a 9-inch pie pan or quiche pan; set aside.

To make pie crust

• Cream butter and sugar until fluffy, about 2 minutes. Add egg, and mix.
• Sift flours, baking powder, salt, and cardamom over the butter mixture and mix until combined.
• Place the dough on the prepared pan. Lay a piece of plastic wrap over the dough and press down to spread it into an even layer across the bottom and up the sides of the pan. (That way you don't touch the dough directly. It makes spreading the dough easier.)

To assemble pie

• To make pie filling, whisk crème fraîche, sour cream, sugar, egg, and vanilla extract until it becomes a pourable consistency. Pour half of the cream filling onto your pie crust in the pan. Swirl to spread it on the bottom of crust.
• Combine blueberries with cornstarch in a bowl and toss. (If you are using fresh blueberries, give them a rinse beforehand so that the cornstarch will adhere to the berries.)
• Scatter blueberries across the filling and pour the remaining cream filling over the blueberries. Put the pie on a large baking sheet and put it in the oven. Bake for 40-45 minutes or until the pie crust is golden brown. The center of pie filling will jiggle a little bit, but it will set slowly as the pie cools.
• Let the pie cool on a wired rack. Serve the pie warm or at room temperature. You can also chill it in the refrigerator and serve it cold.