In a large bowl combine 1-1/4 cups of the flour, the yeast, and the salt. Add 1 cup warm water and oil. Beat with an electric mixer on low speed for 30 seconds, scraping bowl constantly. Beat on high speed for 3 minutes. Using a spoon, stir in as much of the remaining flour as you can. Turn dough out onto a lightly floured surface. Knead in enough remaining flour to make a moderately stiff dough that is smooth and elastic (6 to 8 minutes total). Divide dough in half. Cover and let rest 10 minutes.
On a lightly floured surface, roll each half of dough into a 13-inch circle. Transfer dough to greased baking sheets. Set aside.
For filling, pat spinach dry with paper towels. In a large mixing bowl stir together spinach, ricotta cheese, pepperoni, salami, Parmesan or Romano cheese, basil, garlic powder, and pepper. Spread filling on half of each dough circle to within 1-inch of edge.
Moisten edges of dough with water. Fold dough in half over filling. Seal edges by pressing with tines of a fork. Flute edges, if desired. Prick tops. Brush tops with milk.
Bake in a 375 degree F oven for 30 to 35 minutes or until crust is lightly browned. Makes 6 servings.