Place the butter in a glass sandwich-size container such as this. Microwave until melted, about 50 seconds.
Mix in the vanilla, stevia, milk and egg. Whisk until smooth.
Mix in the coconut flour, cinnamon and baking powder.
Use a small rubber spatula to spread the batter evenly in the container.
Microwave, uncovered, for 90 seconds.
Remove from the container to a cutting board, bottom side up, and allow to cool for 5 minutes.
Fry the bread:
Meanwhile, in a shallow bowl, whisk the egg with the milk, and heat 1 tablespoon butter in a nonstick skillet over medium-low heat.
Dip both sides of the keto bread in the egg mixture. When butter begins to foam, add the soaked bread. Cook over medium-low heat (not higher) until golden-brown, pressing on the middle of the bread with a spatula, 3-5 minutes per side.
Cut into two triangles and serve. The keto French toast is excellent as is, but you can drizzle it with sugar free syrup and dust with Swerve Confectioners if you wish.