1/2 cup Unsalted Butter or Coconut Oil, at room temperature, plus extra for pan
1/2 cup Natural, Unsweetened Peanut Butter or Almond Butter
1 cup Light-Brown Sugar
1 cup Almond Flour
1 cup Whole-Wheat Flour
1 tsp Baking Powder
1 tsp Kosher or Sea Salt
1 tsp Ground Cinnamon
1 1/2 cups rolled oats (not quick-cooking)
1 cup Almonds, sliced or chopped
Preheat the oven to 350°F. In a sieve set over a bowl or large measuring cup, drain blueberries, reserving juice. Transfer blueberries to a small bowl and mash with a fork until a rough puree forms, leaving some berries whole.
Generously butter or grease a 9- by 13-inch baking pan. In a large bowl, combine butter or coconut oil, almond or peanut butter, brown sugar, and ¼ cup reserved blueberry juice. Using a hand mixer beat until light and fluffy.
In a medium bowl, whisk together almond flour, whole-wheat flour, baking powder, salt, and cinnamon. Stir in oats. Add dry mixture to the butter mixture and mix on low speed until soft, crumbly dough forms. Mix in almonds. Divide the dough into thirds. Press two-thirds of the dough firmly into the bottom of the prepared pan and reserve the remaining one-third for the topping.
Spread the mashed blueberries evenly over the bottom crust, leaving a ¼-inch border around the edges to prevent fruit from sticking to the pan. Crumble the remaining one-third dough over the jam filling. Bake the jam bars until golden brown around the edges, 25-30 minutes. Let cool completely in the pan on a wire rack before cutting into bars. The jam bars will keep, well wrapped, at room temperature for up to 4 days.