For crust: place Pamela's All-Purpose Flour and Nut Flour Blends, sugar, and sea salt into the bowl of a food processor fitted with the chopping blade. Pulse a few times to combine.
Scatter the cold butter cubes over the dry ingredients. Pulse a 5-7 times, or until butter is in small pieces with some larger, pea-sized pieces. With motor running on low, pour the beaten egg through the feed hole and process just until dough comes together into a ball. Lay out a piece of parchment or waxed paper on the counter. Turn dough out onto the clean surface and press together to incorporate any dry bits. Divide the dough into 6 equal pieces. (Keep the food processor handy - it's not necessary to wash it yet.)
Grease the bottom and sides of six 4-inch mini tart pans with removable bottoms. Press the dough into the bottom and up the sides of the tart pans. Freeze until firm, about 15-20 minutes.
While the crusts are in the freezer, preheat oven to 375°F. Place the chilled crusts on a rimmed baking sheet. Prick the bottoms of the tarts with a fork to help prevent the crusts from puffing up and/or shrinking. Bake for 10 minutes. Remove from oven and let cool completely on the pan.
To prepare filling: place the butter and sugar into the food processor. Process until light and fluffy. Stop and scrape sides down as needed. With the motor running, add the eggs, one at a time, through the feed hole. Scrape down sides again, if needed. Add the extracts and sea salt. Process again to combine.
Add the Pamela's Nut Flour and Artisan Flour Blends to the food processor. Process until well-combined, silky, and smooth. Divide the mixture between the mini tart pans. Arrange 6 pitted cherries on top of the filling and press them down a little bit into the filling. The tarts will be full, but will not overflow during baking.
Place tarts, still on the baking sheet, in the oven and bake for 18-20 minutes or until the puffing has puffed up around the cherries and is golden. Let cool. Before serving sift confectioner's sugar over the top. Serve chilled or at room temperature.