Prep Work: Cook quinoa: Bring water and quinoa to a boil in small saucepan with lid on. Reduce heat and simmer covered for 10-15 min. or until water is gone and quinoa is fluffy.
Grease an 8-9" springform or cake pan. Preheat oven to 350 degrees. Cook quinoa (directions in prep work above). In small bowl mix ground flax seeds with an equal amount of water and let sit for 10 min. to make gel.
Pour cooked quinoa into blender, followed by ONLY the milk, eggs, vanilla, butter and flax gel. Blend until smooth.
Now add sugar, cocoa powder, baking powder and salt; blend just until combined.
If using walnuts, sprinkle on bottom of prepared pan. Pour batter into pan.
Bake in center of oven for 45-47 min., or until toothpick inserted in center comes out clean. Cool completely. Run knife around of edge of springform pan before removing side, then cut into wedges. Serve with whipped cream.