The Browned Butter In This Muffin Recipe Creates An Amazing Depth Of Flavor. The Streusel Topping Adds A Nice Crunch And Sweetness. You Can Also Make These Gems With Frozen Raspberries Instead Of Blueberries Or A Mixture Of Both Berries. Try Making A Double Batch And Freezing Some For Later. Just Wrap Each Muffin Tightly With Plastic Wrap Before Freezing For Up To 3 Months.