Heat oven to 350℉/177℃.
Line sheet pans with parchment paper. Set aside.
In a large bowl, whisk brown sugar, all purpose flour, whole wheat flour, almond flour, rolled oats, wheat germ, and baking powder together. Set aside.
In a small bowl, beat vegetable oil, eggs, and vanilla until combined.
Stir wet ingredients into dry ingredients.
Roll out dough to ⅛-inch thick.
Trim edges and cut into rectangles. (We cut ours into 1½-inch x 4-inch rectangles, but feel free to cut yours bigger or smaller.)
Repeat with remaining dough, re-rolling and recutting as necessary.
Place rectangles 2 inches apart on prepared baking sheets.
Spread each rectangle evenly with 1½ teaspoons jam, leaving a ¼-inch border on all sides.
Top with another rectangle of dough.
Press edges together to seal.
Bake for 12-15 minutes, until just starting to brown.