Line an 8-inch square baking pan with parchment paper, allowing the paper to drape over the sides for easy removal.
In a small medium bowl, place the melted butter, natural sweetener, cream cheese, extract, nutmeg and salt. Using a handheld mixer on low speed, combine until smooth. Taste and adjust sweetness to your liking.
Pour the mixture into the prepared baking pan and refrigerate overnight.
The mixture will thicken a lot. Remove from the pan, peel away the parchment, and cut into 1-inch cubes.
Store in an airtight container in the fridge for up to a week or in the freezer for up to a month.