In a small bowl, mix the flaxseed meal with 1⁄4 cup water. Let sit until it is egg‐like in texture, about 5 minutes.
In a food processor, blend walnuts and 3 Tablespoons water. Add the flaxseed meal mixture, maple syrup, and vanilla, and blend until smooth.
Melt the chocolate in a microwave and add this along with cocoa powder to the mixture in food processor and blend until smooth.
In a large bowl, mix the oat flour and baking soda together. Add this then into the food processor and blend until it looks like brownie batter.
Pour into a lined 9x9 inch pan lined with parchment paper. Bake at 350 for about 30‐35 minutes.