Prep your pan: Preheat the oven to 350°F (175°C). Line a 12-cup muffin tin with silicone liners or grease well with nonstick spray.
Cook the add-ins: Warm the oil or butter in a skillet over medium heat. Sauté the onion and bell pepper until softened, about 3–4 minutes.
Add spinach and cook just until wilted. Set aside to cool slightly.
Mix the dry ingredients: In a small bowl, stir together almond flour, baking powder, garlic powder, smoked paprika, a pinch of salt, and pepper. This helps distribute seasonings evenly.
Whisk the eggs: In a large bowl, whisk the eggs with heavy cream until smooth and slightly frothy.
Combine: Add the dry mixture to the eggs and whisk to combine.
Stir in cheese, cooked bacon or sausage, and the sautéed veggies.
Fill the cups: Divide the mixture evenly among the muffin cups, filling each about three-quarters full. Give the pan a gentle tap to remove air bubbles.
Bake: Bake for 18–22 minutes, or until the tops are set and lightly golden. A toothpick should come out with just a bit of moisture, not wet batter.
Cool: Let the muffins cool in the pan for 5 minutes, then transfer to a rack.
They’ll firm up as they cool.
Serve: Enjoy warm, or let them cool completely for meal prep.