Whisk yeast, sugar and warm water together in the bowl of a stand mixer fitted with the dough hook attachment. Let it rest for 5 minutes.
Add in 2 cups of the flour and the salt. Knead until the dough comes together and cleans the side of the bowl. If more flour is needed, add ¼ cup at a time. The amount of flour needed will depend on temperature of your kitchen.
Place dough in a fresh large greased bowl, and cover with plastic wrap. Allow the dough to rise at room temperature until it is doubled in size, about 1 hour.
Preheat oven to 425°F (220°C). Line a baking sheet with parchment paper.
On a floured surface, roll dough into a 10x14 inch rectangle. Lightly flour the top of the dough to keep it from sticking to the rolling pin.
Spread pizza sauce on the top of the dough, leaving a 1.5 inch border around the outside. Top pizza sauce with mozzarella cheese. Top with hot capicola and pepperoni slices.
Whisk egg and water together in a small bowl. Brush egg wash around stromboli border. This will help the dough seal when you roll it. Roll stromboli from it's long end, folding in the two sides as you go.
Carefully transfer stromboli to the baking sheet, seam side down. Brush with egg wash and cut slits at the top of the stromboli so steam can escape. Bake for 25 minutes, or until the center of the stromboli is 200°F (93°F).
Remove from the oven and let it sit for 5 minutes before transferring to a cutting board and slicing. Store leftovers in the refrigerator for up to 1 week.
Don't stress about exact measurements. The dough just needs to be rolled out in a big rectangle, about 10 x 14 inches.
Leave a border around the rectangle. You need to brush an egg wash on the border so that the dough will seal together when you roll it.
Use whichever kinds of toppings you prefer. Don't use too much pizza sauce though. Too much will make the stromboli soggy.