Place 1 tbsp butter in a microwave-safe ramekin or wide mug that is about 4 inches across. Microwave for 20-30 seconds until melted, then swirl it around to coat the bottom and sides.
Add the almond flour, baking powder and salt to the melted butter. Stir with a fork until no lumps remain.
Crack in the egg and whisk vigorously for about 30 seconds until the batter is completely smooth. Tap the ramekin on the counter a few times to release air bubbles.
Microwave on high for 90 seconds, until the top is set and springs back when lightly pressed.
Let the bread cool for 1 minute, then turn it out onto a board and slice it in half horizontally to make 2 rounds.
Melt the remaining 1 tsp butter in a skillet over medium heat. Toast the rounds for 1-2 minutes per side until golden brown and crisp around the edges.