Preheat the oven to 325F and line a mini muffin pan with 20 silicone liners (or use a silicone mini muffin pan).
In a large bowl, whisk togehter the almond flour, sweetener, baking powder, and salt. Stir in the melted butter, egg white, and vanilla extract until the dough comes together.
Roll the dough into 1 inch balls and press into the bottom and up the sides of the prepared mini muffin cups.
Bake 15 to 20 minutes, until puffed and the edges are just golden brown. Remove and let cool 10 minutes, then gently press into the centers to reform the wells.
Cream Pie Filling
Bring the whipping cream to a simmer in a small saucepan over medium heat. In a medium bowl, whisk the egg yolks with the sweetener and salt until well combined.
Slowly whisk about half of the hot cream into the yolks to temper, then slowly return the yolk/cream mixture back to the saucepan and cook until thickened, about 3 to 5 minutes, whisking continuously. It thickens up very suddenly and quickly, so watch it carefully!
Remove from heat and whisk in the butter and vanilla extract. Sprinkle the surface with glucomannan, whisking as you go, to combine well. Let cool to room temperature and then spoon into the cookie cups.
Refrigerate 30 to 60 minutes to firm up.
In a small saucepan over low heat, combine the chocolate chips and butter. Stir until melted and smooth, then drizzle over the tops of the cookie cups.
Alternatively, you can melt the chocolate and butter together in the microwave in 30 second increments, stirring until smooth.
Refrigerate another 10 minutes or so to set the chocolate. Store in the refrigerator in a closed container.