Using a small, serrated knife, carefully cut a circle into the top of your pretzel rolls. I find it’s easiest to cut at an angle in a cone shape. Do not go all the way to the bottom because we don’t want to puncture the sides or the bottom of the bread bowls.
Once the top of the rolls have been removed, if you desire, place them in a resealable bag so they can be served along with the beer mac later. Gently pull out pieces of the bread with your fingers, making sure to leave at least ½” on all sides of the bowl. If you accidentally rip out too much, or make a hole, no worries. Use a piece or two of the bread you’ve been pulling out to push into the hole and mend it. Put the cut bread bowls into a resealable bag as you did with the tops so they stay as fresh as possible while you cook the mac and cheese. Set aside.
In a large pot, melt the butter over medium heat. Slowly sprinkle in the flour, whisking until combined. Allow the flour to toast in the butter for 2 to 3 minutes. It will start smell nutty and begin to brown when it’s toasted.
Gradually add heavy whipping cream, then beer, whisking the entire time. Bring mixture up to a low boil, continuously whisking until it has thickened. This takes about 10 minutes.
Remove from heat and add salt, garlic powder, onion powder, black pepper, ground mustard, cayenne, paprika, and nutmeg. Stir to mix.
Add in shredded cheddar and stir until it has completely melted, forming your cheese sauce.
Add cooked pasta to the sauce and stir with a wooden spoon until it is spread throughout.
Fill each pretzel roll with the beer mac.