Preheat the oven to 325ºF and line two baking sheets with silicone mats.
In a large bowl, beat the butter with the sweetener until light and fluffy, 1 to 2 minutes. Beat in the egg and vanilla until well combined.
Add the almond flour, baking powder, and salt and beat until the mixture is uniform, scraping down the sides of the bowl and the beaters as necessary.
Using about 2 teaspoons of dough at a time, roll into small balls and place an inch apart on the prepared baking sheets. Press down to flatten slightly.
Bake 15 to 20 minutes, switching the position of the pans halfway through baking, until the edges are golden brown.
Remove the cookies and let cool for 5 to 10 minutes.
Notes
- Use room temperature ingredients: This ensures a smooth, well-combined dough and even baking. - Don't overmix: Once the almond flour is added, mix just until combined to keep the wafers tender. - The cooling trick: Returning the wafers to the turned-off oven after the initial bake helps them crisp up perfectly without over-browning. Keep an eye on them to prevent excessive browning. - Storage: Store cooled wafers in an airtight container at room temperature for up to 5 days, or freeze for up to 2 months.Nutrition information is an estimate, calculated automatically. Values vary with brands, substitutions and portion sizes.