Drizzle the oil into a tall straight mug, about 3.5 inches wide and 5 inches tall. Brush the oil around the edges to grease the mug.
Place the eggs, almond flour, baking powder, and salt in the mug. Whisk with a fork until very smooth. Tap the mug on the counter to remove air pockets.
Microwave on high heat for 3 minutes. Shake the bread loaf out of the mug. Slice with a serrated knife and serve.
Wrap well and store in the refrigerator.
Video
Notes
Make multiple batches by tripling or quadrupling the recipe and whisking the batter in a large bowl. Then pour the batter into various oiled mugs and microwave. Add 1 minute cook time for each additional mug.