For the glaze, combine the ketchup, vinegar, cumin, Worcestershire sauce, hot pepper sauce and honey, set aside.
Place oven rack to middle position; heat oven to 350 degrees F.
Heat butter in 10-inch skillet over medium-high heat until foaming; add onion and bell pepper and cook, stirring occasionally, until softened, 4 to 5 minutes. Add garlic and cook, stirring, until fragrant, about 1 minute. Transfer mixture to small bowl, set aside to cool.
In a small bowl, whisk egg with molasses, salt, pepper, celery salt, mustard, Worcestershire sauce, 1/4 cup of the evaporated milk and 1/2 the glaze mixture, until combined. Gently break-up ground beef in a large bowl. Add bread crumbs, parsley and cooked onion, bell pepper and garlic. Pour egg mixture over meat mixture and mix gently with hands until thoroughly combined, about 1 minute. If mixture sticks to bowl, add additional evaporated milk, 1 tablespoon at a time, until mixture doesn't stick. Be careful not to overmix, and avoid squeezing the meat.
Transfer meat mixture onto the center of a shallow parchment paper-lined baking sheet or pan and form into a 9- by 5-inch loaf shape, avoiding air pockets. Smooth top and edges of meat loaf with moistened spatula. Bake at 350 degrees F until meatloaf is to medium doneness, an instant-read thermometer inserted into center of loaf reads 155-160 degrees F, about 55 to 65 minutes. Brush the remaining glaze onto the meatloaf after it has been cooking for about 10 minutes. Remove from oven, let stand 15 minutes. Transfer to a platter, and cut into thick slices.