Place the milk and sugar/honey in a small saucepan and heat the milk over medium heat until it reaches 100-110℉. Stir periodically so that the sugar dissolves.
Add the flour, salt, onion powder, garlic powder, and oregano to the bowl of a stand-mixer. Mix on low with the paddle attachment.
Add the egg, oil, and warm milk. Mix on low speed. While the mixer is running, add the yeast granules. Once combined, turn the mixer up to medium speed and allow the dough to mix for 3-5 minutes.
The resulting dough should be smooth, soft, and slightly tacky to the touch. Lightly flour a clean work surface. Lightly flour your hands and transfer the dough onto the floured work surface.
Pat the dough into a rectangle. The exact size is not too important, but you don't want a square and you want the dough to be just a little over 1/4" thick. Aiming for a 10x16" rectangle is a good place to start.
Once the rectangle has been shaped, layer on the sauce, cheese, pepperoni, and garlic salt. Leave a 3/4" rim around the outside of the rectangle that is free from any toppings. On one of the long sides, leave at least a 2" rim.
Starting on the long side that has a 3/4" rim, start rolling the dough like you would for cinnamon rolls. Roll it as tight as possible, shoving the toppings back under each roll of dough as you work. As you roll, the toppings will probably push into the 2" rim on the other long side, but just make sure there is at least a 1/2" rim left by the time all the dough has been rolled into one log.
Roll the dough log so that the seam is on the bottom of the stromboli loaf. Tuck either end of the loaf tightly under the stromboli loaf. You can press the seams with warm water to further help them seal. Transfer the stromboli onto a pizza stone or parchment-lined baking pan.
Cover the stromboli with a lightly oiled piece of plastic wrap or parchment paper. Set it in a warm area to proof (67-75℉) for 20-30 minutes. While the stromboli is proofing, preheat the oven to 400℉.
Once proofed, uncover the stromboli and brush it lightly with olive oil. Sprinkle on more garlic salt, sesame seeds, and dried herbs if desired.
Bake for 25-30 minutes. The outside should turn golden brown and feel firm to the touch. If the stromboli is not browning or seems too dry, brush the loaf with more olive oil during baking or immediately after it comes out of the oven.
After removing the stromboli from the oven, allow it to cool for 15-30 minutes. The longer you let it cool, the less messy your slices will be as the cheese has time to set-up.
Leftovers can be stored in an airtight container in the fridge for up to 5 days. They can also be frozen for later!