Toast bread crumbs: In a large frying pan over medium heat, cook crumbs with oil and 1/8 tsp. each salt and pepper, stirring often, until crumbs begin to crisp, 4 to 5 minutes. Add paprika and cook, stirring, until crunchy, 2 to 4 more minutes. Pour from pan to a bowl and let cool; then seal in a lidded container or resealable plastic bag.
Make sauce: Melt butter in a medium saucepan over medium-high heat. Add flour and remaining 1 tsp. salt and 1/2 tsp. pepper; whisk until bubbling and light tan, 1 1/2 to 2 minutes. Add milk and cook, whisking, until sauce bubbles and thickens, 3 to 5 minutes. Remove from heat, add cheese, and whisk until melted. Let cool, then transfer to a lidded container and chill in refrigerator or cooler.
Pour no-drain pasta into a 12-in. cast-iron skillet or other large, deep frying pan on a camp stove; add 3 cups cold water. Cook over high heat, stirring often, until all but about 1/2 cup water is absorbed, 10 to 15 minutes. (For regular pasta, cook in a large pot of boiling water until just tender. Set aside 1/2 cup cooking water; drain pasta and return to pot with reserved water.)
Add cheese sauce to pasta and bring to a simmer, stirring often. Spoon into bowls and scatter bread crumbs over each serving.
*Whirl a few slices of bread in a food processor to make crumbs. Find Pronto pasta at well-stocked grocery stores.
Make ahead: Through step 2, up to 3 days.