In a large Dutch oven or stockpot over low heat, melt butter. Stir in flour; stir until smooth and bubbly. Gradually add milk, stirring constantly, until sauce has thickened. Add potatoes and onions. Continue to cook, stirring constantly, until soup begins to bubble. Reduce heat; simmer gently for 10 minutes. Add remaining ingredients; stir until cheese is melted. Serve baked potato soup immediately.
My family loves this recipe! It isn't necessarily "hard" to make, you just have to make sure you stir the milk constantly so that you don't scorch it. It reheats well although I like to garnish with a little extra cheese and bacon because the bacon will lose a little of its crispiness once you add it to the soup.