Preheat the oven to 325°F. Line a baking sheet with aluminum foil for easy clean-up and place an ovenproof rack over top; spray the rack generously with nonstick cooking spray.
Whisk the egg and cream together in a medium bowl. Stir in the bread and mash with a fork until the bread is broken down. Set aside.
In a stand mixer fitted with the paddle attachment, beat the pork, garlic, pepper, salt, and baking powder on high speed until smooth and pale, about 2 minutes, scraping bowl as necessary.
Add the bread mixture to the mixing bowl and beat on high speed until smooth and homogeneous, about 1 minute, scraping the bowl as necessary.
Add the beef and mix on medium-low speed until just incorporated, about 20 seconds, scraping the bowl as necessary.
Using wet hands, form the mixture into 1½-inch round meatballs and place on the prepared rack. Bake for about 25 minutes, until just done.
Meanwhile, in a large skillet, whisk together the ketchup, brown sugar, water, cider vinegar, Worcestershire sauce, shallot, garlic, salt, and pepper. Bring to a boil, then reduce the heat and simmer until thickened, 10 to 12 minutes.
Add the baked meatballs to the sauce and simmer until warmed through. Transfer the meatballs to a serving platter, spear with toothpicks, and spoon the sauce over top. Garnish with parsley, if using. Serve warm.
