Preheat oven the to 375°F. Then prepare a 8" round cake pan by greasing, dusting with flour, and lining with parchment paper. The parchment paper will keep the cake from sticking to the bottom and help with even baking.
In a large bowl, mix together the whole oats, room temperature orange juice, orange zest, and maple syrup. Then set aside for later. You want to do this first so that the oats have plenty of time to soften up in the liquid mixture.
Combine all the ingredients of the granola topping, mix well, and set aside.
In a different medium size bowl, sift together the flour, cornstarch, baking powder, baking soda, and salt. Then add the almond flour and whisk all the dry ingredients together. Finally, toss in the dried cranberries and mix again.
Add the brown sugar, ground flaxseed meal, oil, white vinegar, and vanilla to the oat mixture. Then mix well to combine.
Now, add the flour mixture to the wet oat mixture and fold together being careful not to overmix, but still making sure to incorporate well.
Pour the batter into the prepared pan. Then sprinkle the top of the cake with the granola mixture making sure to spread it out evenly.
Bake at 375°F for 50 to 55 minutes until golden brown. A cake tester or toothpick should come out clean when done. Allow the cake to cool on a wire rack for about 20 minutes before removing from the pan.
Store the cake covered at room temperature for 2-3 days. If you are storing the cake for longer than 3 days put it in the fridge on the third day to keep for up to a week. The cake can also be stored in the freezer for up to 3 months in a sealed freezer bag or wrapped well in plastic wrap.