In a mixing bowl, combine flour, sugar, salt, and yeast. Add water, milk and butter; beat on low until well combined.
Mix on low with a bread hook attachment until smooth and elastic, 6-8 minutes. You can also knead by hand on a well-floured surface for the same amount of time.
Place in a greased bowl. Cover and let rise for 1 hour or until doubled in size.
Meanwhile, in a skillet, cook sausage and hamburger meats until no longer pink; drain and cool.
Mix the cooked meats with chopped Canadian bacon, mozzeralla, and 2 eggs; set aside.
Punch dough down; divide in half. Roll each half into a 15 inch by 10 inch rectangle on 2 separate baking sheets.
Spoon half of the meat filling down 1 side of each dough sheet. Fold the dough over the filling and pinch the edges to seal. Cut 4 long strips on top of each stromboli.
Beat remaining egg and brush over the top of the loaves then sprinkle with Parmesan.
Cover and let rise until doubled, another 45 minutes.
Bake at 375 degrees Farenheit for 20-25 minutes or until golden brown. Slice and serve warm with a side dip of marinara sauce.