Preheat oven to 350°F (175°C). Adjust 2 racks to the center of the oven. Line 2 rimmed baking sheets with silicone mats or parchment paper coated with cooking spray.
In a large bowl, whisk the egg whites until lightened and frothy, a few seconds. Add the powdered sweetener, vanilla and almond extracts, and 1/8 teaspoon salt. Whisk just until the sugar has dissolved and the texture is like a thin mayonnaise, 2 to 3 minutes. Fold in the almonds to coat.
Drop tablespoon-sized mounds of the almond mixture 1 1/2 inches apart on the prepared baking sheets. Use a spoon to flatter each mound to about 2 inch rounds without creating gaps between the sliced almonds.
Bake until light golden brown, 10 to 13 minutes.
Cool the cookies on the sheets for 1 minute; then slide the silicone mat with the cookies onto cooling racks or the countertop to cool completely, 20 to 30 minutes.
In a microwave-safe bowl, combine the chopped chocolate and coconut oil, then microwave for 20 seconds to melt. Stir or microwave for another 10 seconds if not melted. Stir until smooth and glossy.
Set out a piece of parchment paper on a clean surface. Dip one end of each cookie into the melted chocolate, then place it on the parchment paper, sprinkle with flaky sea salt, and let set, 30 to 40 minutes. Enjoy!