Preheat oven to 325 degrees.
Using butter, generously grease a cast iron skillet or 8 x 8 pan. (*Note 1)
Add the almond flour, coconut flour, nutritional yeast, sweetener, salt, baking soda and to a large mixing bowl, and stir until combined.
Whisk in the eggs and heavy cream until fully combined.
Add the melted butter and mix together until all ingredients are incorporated.
Pour the batter into the greased cast iron skillet and spread evenly. Put into preheated oven and cook 25-30 minutes until golden brown on top.
Allow cornbread to cool for approx. 10 minutes, before serving.