Grease or spray a 9-inch tart pan (preferably a fluted one) or a 9-inch round cake pan.

Preheat oven to 375 degrees F.

Combine almond flour, all-purpose flour, baking powder, cinnamon and kosher salt in a medium bowl. Whisk to combine. Set aside.

Combine butter, brown sugar and 1/4 C. of granulated sugar in the bowl of your stand mixer and beat at medium-high speed until the ingredients are well combined and become light and fluffy. This will take several minutes. Use a spatula to scrape down the sides of the mixer bowl. Add the eggs one at a time with the mixer on medium speed.. Mix until the first egg is totally combined before adding the second egg to the butter mixture. Add the vanilla. Increase the speed of the mixer to medium-high and mix until the mixture has nearly doubled in volume and the color of the mixture has lightened.This will take 4 to 5 minutes. Fold in the almond flour mixture and mix until no dry pockets of flour remain.

Using your hands, gently mix the 2 cups of fresh blueberries into your batter. You want to keep as many of the berries whole as you can. Spoon the batter into the prepared pan. Sprinkle the remaining 3 T. of granulated sugar on top of your cake. (This will seem like a lot of sugar, but it will give a nice crunch to the top of the cake as it bakes.)

Bake at 375 degrees F. for 35 minutes. Your cake is done when the top is a pretty brown and the sides of the cake begin to pull away from the sides of your pan. You can also check the cake for doneness with a toothpick or wooden skewer. You want the the toothpick (or skewer) to come out clean when inserted into the middle of the cake. If your cake top begins to get too brown toward the end of the bake, you can loosely tent the top of the cake with foil.

Remove the cake from the oven and let it cool completely before cutting.