Preheat oven to 350°F (175°C). Grease and line an 8×8 or 9×9-inch baking pan, or use muffin tins if preferred.
In a large bowl, cream together the softened butter, allulose, molasses, and vanilla.
Add eggs one at a time, mixing well after each addition.
In a separate bowl, whisk together the baking powder, baking soda, cinnamon, nutmeg, salt, and almond flour.
Gradually mix the dry ingredients into the wet mixture until well combined.
Fold in the grated carrots and chopped nuts.
Pour batter into the prepared pan and smooth the top.
Bake for 30-40 minutes or until a toothpick inserted in the center comes out clean.
Allow the cake to cool completely before frosting.
In a bowl, beat together the cream cheese and add butter until smooth and creamy.
Add the powdered sweetener, and salt. Mix until light and fluffy.
Spread evenly over the cooled carrot cake.