Preheat the oven to 350 degrees F. Line a 9-by-13-inch baking dish with aluminum foil with a 1-inch overhang on all sides. Spray lightly with baking spray.
Combine both flours, oats, wheat germ, chia seeds if using, salt and cinnamon in a medium bowl. Set aside.
Combine the peanut butter, brown sugar, vegetable oil and egg white in another medium bowl. Beat with a hand mixer until creamy, about 2 minutes. Add the dry ingredients and beat on low until a wet and sandy mixture that holds together when squeezed. Turn the dough out into the prepared pan and press into an even layer. Bake until golden, 25 to 30 minutes. Let cool completely. Drizzle with the chocolate. Let the chocolate harden and break into eighteen 2-inch even pieces.