Lightly coat the inside of a 12-16 ounce microwave-safe glass or ceramic mug with ½ teaspoon olive oil or cooking spray. Tear the cooked lasagna noodles into pieces that sit flat in the mug. Set the mug on a microwave-safe plate to catch any bubbling sauce.

Spoon a thin layer of marinara into the bottom of the mug, then add a layer of noodle pieces, cottage cheese, crumbled Italian sausage, and mozzarella. Repeat the layers until ingredients are used, finishing with marinara and mozzarella on top. Press gently with a spoon and leave at least 1 inch of headspace for bubbling.

Loosely cover the mug with a microwave-safe cover or damp paper towel and microwave on HIGH (1,000 watts) for 1 minute. Carefully uncover, give the center a gentle stir, then re-cover and microwave 30-60 seconds more until the sauce bubbles at the edges and the mozzarella is fully melted. For lower-wattage microwaves, add 15-second bursts and check between each.

Let the mug sit covered on the counter for 1 minute before eating — the residual heat finishes warming the center and the layers settle. Use an oven mitt because the mug will be very hot. Top with fresh basil or a sprinkle of Parmesan if desired.