To make the meatballs, combine the ground beef, breadcrumbs, half & half, parsley, mustard, salt, black pepper, and eggs in a large mixing bowl. Mix together well with your hands. Scoop out 1-tablespoon portions and roll them into balls with your hands. Place the meatballs onto parchment-lined baking sheets and place in the freezer for 5 to 10 minutes. This will help the meatballs stay together as you brown them.
To brown the meatballs, heat the canola oil in a heavy pot or large sauté pan over medium-high heat. Add the meatballs in batches, making sure not to overcrowd the pan. Cook, turning the meatballs to make sure they brown all over, 5 to 7 minutes per batch. Drain on paper towels.
For the sauce and to finish the meatballs: In a large pot over medium-high heat, add ketchup, brown sugar, and whiskey and bring to a boil. Add the meatballs and bring to a simmer. Cover and cook until the meatballs are heated through, 8 to 10 minutes.