- Preheat oven to 400 degrees.
- Cream butter and sugar in a stand mixer fitted with the paddle attachment for 5 minutes on medium speed. Add egg, sorghum, and vanilla extract, and paddle for another five minutes.
- Add dry ingredients and mix until homogenous.
- Scoop dough into small rounds and flatten on a parchment-lined cookie sheet.
- Bake until barely browned around the edges, about 6–12 minutes, depending on your oven and size of each cookie (the cookies should still be very soft when done baking), then cool.
- Mix all ingredients together in a stand mixer fitted with the paddle attachment until completely mixed.
To Finish and Assemble
- Mound filling in the middle of 1 cookie, place second cookie on top, and squeeze lightly to evenly distribute.