To prepare burritos: Preheat the oven to 375 degrees. Lightly coat a 9-13-inch baking dish with nonstick spray.
In a large skillet, heat 1 tablespoon oil over medium heat. Add green onions and garlic; cook until softened, 2 to 3 minutes. Add spinach; cook until leaves are wilted. Stir in coriander, nutmeg, grated cheese and cream cheese. Remove from heat.
To keep tortillas from cracking, place them on a baking sheet (overlapping is fine) and heat them in the oven for a minute or two.
Place 1/3 to 1/2 cup of filling on the lower half of a warm tortilla, fold the bottom up and the sides in to encase the filling, roll it up and place it seam-side down in the baking dish. Repeat with remaining tortillas and filling.
Brush the tops of the burritos with the remaining 2 teaspoons oil, cover tightly with aluminum foil and bake until hot, 20-25 minutes.
Meanwhile, prepare hot sauce: In a heavy saucepan or skillet, heat oil over high heat until it is almost smoking. Add onion, bell pepper and salt to taste. Cook, stirring often, until bell pepper is blistered and beginning to brown, about 4 minutes. Add cumin, coriander and cayenne or red pepper flakes, stirring to combine. Remove from heat.
Transfer mixture to a blender or food processor. Add tomatoes; puree.
Return the sauce to the pan; add cilantro and salt to taste. Simmer, stirring occasionally, for about 10 minutes, partially covering the pan to avoid splatters.