Set your vegetable layer and sauteed riced cauliflower aside (these can be made 1-3 days in advance and covered/stored in fridge until ready to use.)
Preheat oven to 350 F or omit this step if making ahead of time
Cook 1 cup penne according to pasta directions, less 1 minute or to al dente firm; once done cooking, strain and use a light amount of sauce to just coat the noodles. Set aside
Meanwhile, make your egg/cheese mixture by combining 1 beaten egg with 1/2 cup ricotta and 1/3 cup cottage cheese (you can alter the cheese ratios to fit your liking); set aside
Prepare your lasagna dish by spraying the bottom and sides with cooking oil or spreading olive oil
Measure 1/4 cup sauce and spread evenly across the bottom of pan
Place your lasagna noodles to cover bottom of dish in one layer. Trim to fit
Spread about half of your egg/cheese mixture in an even layer over lasagna noodles
Add half of your vegetable mixture evenly. Add half of your riced cauliflower. If you haven't seasoned your veggies while cooking, add a pinch of salt throughout
Add 2 tbsp parmesan cheese and 1/3 to 1/2 cup mozzarella
Layer another set of noodles. Spread almost all of your egg and cheese mixture (reserving two tablespoons or so for the top layer)
Repeat steps for veggies, rice cauliflower, parmesan and mozzarella as above
This time, place small dollops of sauce across the top (see photo)
For final layer, use your cooked and lightly sauced penne to create one even layer, spooning on the penne with a large spoon or spatula
Sprinkle a bit of parmesan and the remaining 1/2+ cup of mozzarella cheese, being sure to create a mozzarella "border" around the edge of the baking dish (this will create those chewy, crispy edges; fill in the top with cheese and then spread your remaining bit of egg/cheese mixture in small bites across the top
Cover tightly with foil -- either place in fridge until later, or place in pre-heated oven for 20 minutes
Remove foil, increase oven to 375 F and cook 20 more minutes or until sides of lasagna are light brown and crispy