Butter a 9” deep-dish, glass pie plate or oven safe skillet. Preheat oven to 350 degrees Fahrenheit.
Mix the blueberries, 1/4 cup of the sweetener, lemon juice, and cinnamon and pour into the prepared pie pan or skillet. Put the fruit in the preheated oven and bake 25 - 30 minutes until the blueberries are beginning to boil and bubble up around the edges of the pan.
While the blueberries are baking, mix the almond flour, coconut flour, Keto Chow, baking powder, cinnamon, nutmeg and salt and set aside.
In a separate bowl mix the eggs, sour cream, butter, and the remaining 1/4 cup sweetener.
When the blueberries are almost ready, mix the wet ingredients into the dry ingredients.
Carefully remove the pie pan from the oven and place dollops of the topping on the hot blueberry filling, like drop biscuits, starting from the center and working around. Gently smooth the tops so they are all the same height.
Return the pan to the oven. For best results, place the pie pan on a cookie tray to catch any spills if it boils over.
Bake for about 20 minutes more, until the topping is beginning to brown around the edges and springs back when touched in the center.
Remove cobbler from the oven and allow it to cool for at least 10 minutes.
Serve warm or at room temperature with whipped cream or a scoop of sugar-free, vanilla ice cream.