In a food processor pulse together all-purpose flour, finely ground blanched almonds, toasted wheat germ, light brown sugar, kosher salt, and baking powder. Add cold, unsalted butter, and process until largest pieces are the size of small peas. With machine running, add low-fat buttermilk until dough just holds together. Pat into a disc, wrap in plastic, and refrigerate for 1 hour (or overnight).
Preheat oven to 375 degrees. On a lightly floured surface, roll out dough 1/8 inch thick. Fit into a 9 1/2-inch tart pan with removable bottom. Trim edges flush with pan and prick holes in dough with fork. Freeze for 15 minutes. Line with parchment paper and fill with pie weights. Bake for 25 minutes. Remove parchment and weights and bake until golden brown and dry, 15 to 20 minutes more. Let cool.
Puree part-skim ricotta with 1/4 tsp. salt, cinnamon, and 1 Tbsp. honey. Spread into cooled shell. Stir 2 Tbsp. honey gently into blueberries and arrange on top of tart. Chill for 2 hours.