Mix the dry ingredients - almond flour, cinnamon, pumpkin spice, baking powder, powdered sweetener and crushed walnut pieces - in a small bowl with a fork.
Add the wet ingredients- grated carrot, egg, melted butter, heavy cream. Stir with a fork until a batter forms.
Fill the carrot cake batter into 2 well-greased ramekins (I used melted butter) or 1 Pyrex glass bowl. Microwave 5 minutes at 800W (or 6 minutes at 700W). See oven instructions in the recipe notes below.
Turn the cake upside down onto a plate and serve with cream cheese frosting (cream cheese mixed with optional powdered sweetener). Decorate with more crushed walnuts and grated carrots. Or eat straight from the ramekin!
