Toss broccoli with half the butter to evenly coat. Place on baking sheet. Bake in 375°F standard oven 8 to 10 min. or until browned but still firm. Set aside.
Brush bottom of 1-qt. baking pan with remaining butter. Sprinkle with 2 Tbsp. coarse cracker crumbs.
Fold broccoli and pimiento into prepared mac & cheese. Spoon into prepared pan. Top with combined cheddar, bacon and remaining coarse cracker crumbs.
Reduce oven temperature to 350°F. Bake mac & cheese 8 to 10 min. or until topping is golden brown.
Spoon into individual serving bowls.