Make It Now:

1. Preheat oven to 400°F. Cover a rimmed sheet pan with parchment paper or foil for easy clean-up.
2. In a large bowl, use a fork to stir together the breadcrumbs, grated Parmesan, parsley, carrot, onion, garlic, salt, and pepper.
3. Then crack the eggs and add the ketchup to the middle of the bowl. Whisk with the fork until eggs are beaten. Then stir to combine with the entire mixture.
4. Add in the ground beef. Use your hands to combine well but do not overmix.
5. Roll meat mixture into meatballs, using about 2 tablespoons of mixture per meatball. They will be about 1 ½ inches in diameter. Place on sheet pan, leaving a little room between each one. 
6. Bake for 18-20 minutes or until cooked through. Cut one open and make sure there is no pink in the middle to assure doneness. Internal temp should be 160 degrees F.

Freeze For Later:

Option 1 (Uncooked Meatballs): Follow steps 1-5. Store uncooked meatballs in a freezer bag or container in a single layer. Or, if stacking meatballs in a container, divide single layers with parchment paper. Seal and freeze.

Option 2 (Fully Cooked Meatballs): Follow Steps 1-6. Let cool. Freeze the cooked meatballs in a freezer bag or container in a single layer. 

Prepare From Frozen:

Option 1 (Uncooked Meatballs): Thaw the uncooked meatballs. Follow Step 1. Bake according to directions in Step 6. 

Option 2 (Fully Cooked Meatballs): When ready to warm up the fully-cooked meatballs, thaw in the refrigerator. Warm up over low to medium-low heat on the stove in some marinara sauce. Another option, although not the preferred method, is to defrost in the microwave. Lastly, you can warm up the meatballs in marinara sauce in the slow cooker over Low heat for about 2-3 hours.