Preheat the oven to 350°F (175°C). Grease a standard loaf pan with butter or non-stick spray and set aside.
In a large mixing bowl, combine almond flour, keto sweetener, and baking powder. Whisk together until well mixed, aiming for an even, fine mixture with no lumps.
2 cups almond flour
Add eggs one at a time to the dry mixture, whisking thoroughly after each addition until the batter is smooth and slightly thickened. The mixture should become pale and slightly viscous.
2 cups almond flour
Stir in the melted butter and vanilla extract, mixing until the batter is uniform with a glossy appearance and no streaks of butter remain.
2 cups almond flour
Pour the batter into the prepared loaf pan, smoothing the top with a spatula. Gently tap the pan on the counter to remove any air bubbles.
Bake in the preheated oven for about 60 minutes, or until the top is golden brown and a toothpick inserted into the center comes out clean. The loaf should feel firm and spring back slightly when pressed.