Preheat the oven to 180C/350F. Line a 12-count muffin tin with muffin liners and grease 10 of them.
In a large mixing bowl, beat the butter, allulose, salt, vanilla extract, and eggs together. Once that has been done, add the milk and mix until combined.
In a separate bowl, sift the coconut flour and baking powder. Combine the wet and dry ingredients and stir until combined. The batter should be thick but pourable. If it's too thick, add extra milk, one tablespoon at a time.
Distribute the batter amongst the 10 muffin pans, filling about ¾ full. Bake the cupcakes on the center rack for 17-20 minutes, until a skewer comes out mostly clean from the center.
Remove the cupcakes from the oven and allow cooling for 10 minutes, before transferring to a wire rack to cool completely. Once cooled, frost.
Notes
* You can also use granulated monk fruit sweetener.** Start with 2 tablespoons and add more if the batter is too thick.TO STORE: Leftover cupcakes can be stored in an airtight container at room temperature for up to five days. If they are unfrosted, cover them with a paper towel to keep them moist. Store them in the refrigerator for up to one week to keep them fresher for longer. TO FREEZE: Freeze leftover cupcakes in a freezer bag for up to six months.