Preheat the oven to 325°F. Line a baking sheet with parchment paper.
Place the butter in a medium, microwave-safe bowl. Microwave on high until butter is very soft, about 30 seconds. It’s OK if it becomes melted.
Add the stevia, vanilla, and salt. Whisk to incorporate.
Add the almond flour. Mix with a rubber spatula or a fork until dough forms. You might find it easier to lightly knead the dough.
Scoop the dough with a 1.5-tablespoon cookie scoop. Shape each cookie with your hands, working the crumbly dough into a smooth ball and then flattening it into a ¼-inch thick cookie, as shown in the video.
Place the cookies on the parchment paper, 1 inch apart.
Bake the cookies until they turn golden, about 12 minutes.
Cool the cookies in the pan for 10 minutes – they will still be soft at this point - then carefully transfer them to a cooling rack and cool for 10 more minutes before serving.
Video
Notes
The dough will be very crumbly, but don't worry about it. Simply shape it with your hands, using it like you would use playdough until it comes together into a cookie. It's a very forgiving dough, and since it does not contain gluten, you don't need to worry about overworking it. However, if you feel that the dough is so crumbly that it's impossible to work with, add a little water - one teaspoon at a time - until it's workable.
You can store these cookies in an airtight container at room temperature for up to 3 days. If you'd like to keep them for longer, it's best to freeze them in freezer bags, separated by wax paper squares.