Preheat the oven to 350º F and line an 8 x 8 pan with parchment paper. Lightly coat the parchment paper with non-stick spray. (see the step-by-step instructions in the post above for the best way to line a brownie pan).
Place the chocolate chips and the olive oil in a microwave-safe container. Microwave the chocolate and oil together in 15-second intervals until the chocolate is melted, stirring after each interval. Set aside to cool slightly.
In a large bowl, measure and sift together the oat flour, protein powder, cocoa powder, cornstarch, baking powder, and salt. Set aside. I sift the dry ingredients because cocoa powder tends to clump. If you don't have a sifter or a fine mesh strainer, you can whisk the dry ingredients and be sure to break up any lumps.
In a medium-size bowl, whisk together the eggs, Greek yogurt, maple syrup, vanilla extract, and the melted chocolate.
Pour the wet mixture into the dry mixture and stir together with a spatula or large spoon until smooth. Allow the batter to rest for 3-4 minutes.
Pour the batter into the prepared pan and bake in the center of the oven for 16-18 minutes. The brownies are done when the edges are set and the middle isn't quite set yet. Remove from the oven and allow to cool completely in the pan. The brownies will finish setting in the pan. Do not overbake.
Once cooled, remove the brownies using the parchment overhang and transfer them to a plate or cutting board that will fit in your refrigerator.