Chocolate Peanut Butter Brownies (gluten-free, 100% whole grain)

Preheat the oven to 350°F (176°C). Spray an 8" x 8" pan with baking spray.
If making these in the food processor, process the oats for a few seconds until powdery. Add the rest of the ingredients except for the chocolate chips and peanut butter. If making these in the blender, first add the liquid ingredients, and then the dry ingredients, except peanut butter and chocolate chips. Either way you do it, process until the oats are well ground.
9 ounces (255 grams) Greek yogurt, 1/4 cup + 2 tablespoons (90 ml) milk, 1 egg, 1 egg white, 3/4 cup (65 grams) rolled oats, 3/4 cup (85 grams) Dutch-process cocoa powder, 1/4 cup + 2 tablespoons unrefined sugar, 1/4 cup (80 grams) honey, 1 1/2 teaspoons baking powder, 1/2 teaspoon salt
Pour the batter into the prepared pan. Sprinkle chocolate chips on top.
1/2 cup (90 grams) semi-sweet chocolate chips
Microwave the peanut butter in a microwave safe bowl on half power until it's easy to spread. Drop spoonfuls of peanut butter onto the batter and create a swirl effect using a knife or toothpick.
1/2 cup (128 grams) natural peanut butter
Bake for 23 - 27 minutes or until a toothpick inserted in the middle comes out clean. Be careful not to confuse a chocolate chip with batter!
Cool completely in the pan and then cut. Store in an airtight container in the refrigerator for up to one week.