Pre-heat oven to 350 degrees.
In a large bowl, whisk together eggs, pumpkin, sugar, oil and 1 teaspoon vanilla extract until combined.
In a medium bowl, sift together flour, xanthan gum (if using), baking powder, baking soda, salt, cinnamon, and nutmeg and mix together.
Add dry ingredients to the wet ingredients and stir to combine. Pour batter into an UNGREASED 9x13 pan and bake at 350 degrees for 30-35 minutes or until a tester comes out clean and the cake springs back when poked.
Cool completely.
To make the frosting, beat together cream cheese, butter and vanilla until smooth. Add in powdered sugar and beat until smooth. Spread frosting evenly over the top of the cake and decorate with gluten free sprinkles (optional).