In a large pot bring 8 cups of salt water to a rapid boil. Add the macaroni stirring occasionally. In a medium saucepan over medium heat melt a stick of butter. Once hot, whisk in the flour, one Tbsps at a time and continue to whisk until mixture is smooth and there are no lumps. Slowly add the milk stirring constantly until combined. Be careful not to boil. Slowly add about 3/4 of the cheese while constantly stirring until combined. You will reserve the remaining ¼ for the topping. Stir 2 Tbsps of WannaRub into the mixture. Once the macaroni is al dente, strain the pasta and return it to the pot. Add the cheese mixture to the macaroni and combine.
Dump the sleeve of crackers into a gallon ziplock bag and you a rolling pin to pulverise into cracker crumbs. Add the remaining cheese to the bag and shake the bag until the cracker crumbs and cheese are combined. Pour the mac and cheese into a 10 x 12 casserole dish and cover with the crumb mixture.
Sprinkle remaining 2 Tbsp of WannaRub over the top of the mac and cheese. Lay a few pads of butter (half stick) on top and place in a 400 degree oven for about 20 mins. Enjoy!!