Start by mixing all of the dry ingredients together in a large mixing bowl. Next, add the pumpkin puree, eggs, vanilla extract, and butter to the same bowl and mix everything together.
Fill each lined muffin cup in the muffin pan with batter. Mix cream cheese, vanilla and sweetener together. Spoon cream cheese filling onto each muffin, using a toothpick to swirl the icing into the muffins.
Bake in the oven for 20 - 25 minutes. Allow them to cool for 5 minutes prior to serving.