1. Oreos Baked Inside Cookies

bakersroyale.com
Get the recipe here.
2. Nacho Lasagna

buzzfeed.com
Uses tortillas instead of pasta sheets. Get the recipe here.
3. Turducken (a chicken inside a duck, inside a turkey)

Get the recipe here.
4. The Veggieducken

Flickr: thesporkful
Get the recipe here.
5. Pecan Pie Inside Chocolate Cake

makinglifedelicious.com
Get the recipe here.
6. Spaghetti Bread

onestopbabygifts.blogspot.com
Get the recipe here.
7. Cupcake Pie

thedomesticrebel.com
Get the recipe here.
8. Meatloaf Eggs

dukanitout.com
Get the recipe here.
9. Apple Pie Baked in an Apple

testadoprovadoeaprovado.blogspot.com
Get the recipe here.
11. Cherpumple (three different pies stuffed in three different cakes!)

12. Mac & Cheese Meatloaf Balls

instructables.com
Get the recipe here.
13. Pumpkin Pie Inside a Cupcake

bakeitinacake.com
Get the recipe here.
14. Ramen Crust Pizza

seriouseats.com
Not to be confused with the ramen burger. Get the recipe here.
15. Reese's Stuffed Oreos

cookiesandcups.com
Get the recipe here.
16. Hoagie Dip

foodnetwork.com
Get the recipe here.
17. The Sushi Cake

nowimacook.com
Get the recipe here.
18. The Pasta Burrito

burrissimo.com
No recipe, but FYI, there's a restaurant chain in California called Burrissimo that specializes in the "Italian burrito."