Preheat oven to 350 degrees.
In a large pot, over medium-high heat, bring two quarts water and 1 teaspoon salt to a full rolling boil. Gradually add macaroni and boil approximately 10 minutes or until pasta reaches desired tenderness. Drain.
Melt butter and olive oil in a saucepan over medium heat. Sauté shallots in butter and olive oil for approximately 2 minutes or until they begin to turn transparent. Add flour to the pan, stirring constantly until a smooth paste forms. Stirring constantly, gradually add milk and continue cooking until mixture is thick and bubbly (mixture should coat the back of a spoon). Add 8 ounces of cheese and stir until completely melted. Remove from heat and add beer, mustard, garlic powder, pepper and remaining salt. Stir well.
Spray a 9” x 9" square glass pan with non-stick cooking spray. In the large pot, combine macaroni and cheese sauce and stir. Pour into 9” x 9" baking dish, cover with foil and place into preheated oven and bake for 15 minutes. After 15 minutes, remove foil and continue cooking, uncovered for another 15 minutes.
Remove macaroni and cheese from the oven. Allow to cool for approximately 5 minutes before serving.