Preheat oven to 350°F and line or lightly grease an 8×8 baking dish.
Add the yogurt, eggs, oat flour, vanilla, and optional maple syrup to a bowl or blender. Mix until completely smooth.
Pour the mixture into the prepared baking dish and smooth the top.
Bake for 35-45 minutes, until the edges are set and the center is just barely jiggly.
Let cool at room temperature, then refrigerate for at least 2 hours before slicing into bars. Or enjoy warm topped with maple syrup or whipped cream!
