Special Equipment Needed:
Preheat the oven to 400 degrees. Whisk salt, baking powder, all purpose flour and rye flour together in a medium bowl. Set aside. Place butter and sugar in the work bowl of a stand mixer. Beat until light and fluffy, about 3 minutes. Add egg and mix until fully combined. Add dry ingredients on low and mix until the dough just comes together.
Transfer dough to a 10 inch fluted tart pan with a removable bottom. Press the dough into the pan and up the sides in an even layer. Transfer to the refrigerator to chill while you prepare the filling.
Combine creme fraiche, egg, sugar, salt and vanilla in a medium bowl. Whisk until fully combined. Pour filling into the crust and scatter blueberries over the top. Bake until the crust is golden brown and the filling is set, about 22-25 minutes. Cool to room temperature before serving.
Calories: 223kcal | Carbohydrates: 31g | Protein: 4g | Fat: 10g | Saturated Fat: 6g | Cholesterol: 63mg | Sodium: 143mg | Potassium: 73mg | Fiber: 2g | Sugar: 16g | Vitamin A: 337IU | Vitamin C: 3mg | Calcium: 43mg | Iron: 1mg