Bring a large pot of salted water to a boil, add the macaroni, and cook according to package instructions. Drain well and set aside.
Meanwhile, melt the butter in a small pot over medium heat. Add the flour and cook, whisking constantly, about 2 minutes. Add the milk and cook, whisking constantly, until the mixture has thickened, about 5 minutes. Remove from heat and let cool slightly.
Combine the cream cheese, mayonnaise, mustard, hot sauce and cayenne in a large bowl and stir until smooth. Add the cooled flour mixture and egg and stir to combine. Add the cheddar cheese, bread crumbs, and pimentos and stir to combine. Add the reserved pasta and stir until completely coated.
Heat oven to 375°. Spoon heaping mounds of the macaroni mixture into the cups of 1 ½ mini muffin tins (about 36 cavities), pressing down lightly so that they are well-packed and resemble little muffins. Bake until bubbling and deep golden brown at the edges, about 10 minutes.
Let cool in pan 5 minutes, then use a knife or skewer to lift each bite from the pan. Serve warm.