Preheat the oven to 425 degrees, and line a baking sheet with parchment paper.
Stretch out the pizza dough to about 15" x 10" onto the baking sheet (wide enough so that the longest side fits the length of the baking sheet.
Heat the olive oil in a saute pan over medium-high heat, and add the kale, onion, and apples. Saute until the onion starts to turn golden and the apples are soft - about 15 minutes. Season with the sugar and pepper.
Spread the shredded Cabot cheddar cheese over the dough, leaving about a 1-inch border all around.
Top the cheese with the Canadian bacon slices.
Spread the kale - apple mixture evenly over the Canadian bacon.
Starting at the bottom of one of the wide edges, carefully roll the bread up, tucking the filling inside as you roll.
Seal the edge with your fingers, and turn the bread so that the sealed edge is underneath (so it won't open up as it bakes).
Brush with some of the beaten egg, and if desired, sprinkle with a pinch or two of sea salt and some poppy seeds. Make about 5-6 cuts into the top layer of the dough to let the steam escape.
Bake the bread on the middle rack, for 15-20 minutes, or until it's golden brown.
Let the bread rest for about 15 minutes before cutting into it.