Pretty easy to make, and very tasty. You'll have some leftover sauce. You can use it for dipping or save it for pizza night some other time. I'd use it within a week.
As I said in the post, you can either do a ladder braid or a jelly roll-type. In this recipe, I'm giving instructions for a ladder braid only.
If you are sure of your yeast, just dump everything in your mixer together. If you're not sure, proof it in the warm water. Once it's happily bubbling away, add all the other ingredients.
Fit the mixer with the dough hook and turn it on to medium low speed. The dough hook will eventually incorporate all the ingredients and then knead the dough.
Check the dough occasionally by stretching it. It should be pretty smooth and extensible when you're done--a total of about 10 minutes.
The dough will be kind of soft, so make sure you have oil up your hands and the dough.
Turn the dough out and shape it into a ball.
Spray the mixing bowl with pan spray or oil and then drop the dough back in, smooth side up. Spray the top of the dough and then cover to let rise in a warm place until doubled, about 1 1/2-2 hours, depending on the temperature in your kitchen.
For the Sauce
Heat a small saucepan over medium heat.
Add the oil--it looks like a lot, but it'll be okay.
Add the garlic and let the garlic get some nice color. Watch is closely so it doesn't burn. Some lovely deep golden brown patches are what you're shooting for.
Dump the tomatoes in, juice and all.
Season with salt, pepper and Italian seasoning.
Turn the heat down to medium low and continue to cook until almost all the liquid is gone. You can stir occasionally during this process, but mostly it will take care of itself.
Taste for seasoning and adjust if necessary.
Puree using an immersion blender (it's really not enough to put in the regular blender). You can always choose to keep it chunky, if you want.
Let cool to room temperature.
To Assemble and Bake
Once the dough has doubled, press out all the gases and then turn it out on a pan-sprayed surface.
Roll the dough out to about a 12"x15" rectangle (no need to whip out the ruler).
Spread the sauce in a strip about 3" wide down the center of your rectangle. Top with sliced mozzarella, pepperoni and the shredded mozzarella. Repeat the layers of cheese, pepperoni and cheese once more (to get extra meaty-cheesy goodness. Or you can just stop at the first layering).
Use a pizza cutter to cut 1" strips in towards the filling. Stop the cuts about 1" from the filling to help guard against blowouts.
Fold some of the dough over the top and bottom edges of the filling to keep it from leaking, and then cross the strips over, one over the other, all the way down until the loaf is completely Sewn Up.
Use a couple of large spatulas to transfer the loaf to a baking stone or a greased cookie sheet.
Brush the top of the loaf with olive oil and cover. Let rise for about 35-45 minutes.
Preheat the oven to 375F
Once the dough has risen again nicely, bake on the center rack until the internal temperature in the center of the loaf reaches 205F, give or take just a few degrees.
Remove the loaf from the oven and brush again with some olive oil.
Let cool and then serve at room temperature or reheat to serve hot. Don't serve it straight from the oven, or the dough won't have had a chance to set up and will taste gummy.