Sift flour, icing sugar and almond flour. Measure out the required amounts into a stand mixer bowl. Add salt.
Using the paddle attachment for your stand mixer, add the butter and mix on low until the mixture becomes a bit grainy.
Add the egg and vanilla extract and continue mixing. Stop when the dough is just barely combined.
Finish the dough by combining the remaining dry ingredients left in the bowl on the counter with your hands. Make 2 dough balls and cover them in plastic wrap. Chill for 2-3 hours.
Roll out the dough on a floured surface until it's 1/4'' in thickness. Grease your 8'' tart pans with butter. Place your rollout dough on the tart pan. Press the dough into the tart pan to make sure its secure. Cut the excess dough using a sharp knife. Place the dough in the fridge for 15 min. Pierce the dough with a fork, not all of the way through the dough. Make several fork dents in the dough. Preheat your oven to 375 degrees F.
Bake your tart for 18 min. If you're making mini tarts, bake for 8-12 min. Remove and let cool. Brush the tart with melted white chocolate and let the chocolate solidify before filling your tart with the filling. This will prevent the tart shell from become soggy.