Blueberry Streusel Muffins

We thought it would be easy to find great recipes for something as popular as blueberry muffins, but most baked up dry or spongy, with an ugly blue (or even green!) color and weak blueberry flavor. We wanted a tender, cakey muffin bursting with berries and crowned with chewy nuggets of streusel. Here’s what we discovered:

Test Kitchen Discoveries

• We used the test kitchen’s favorite blueberry muffin recipe but replaced the usual sour cream with buttermilk. This created muffins with a sturdy-but-light texture that was able to support the weight of our streusel.
• Using juicy, fresh blueberries made our muffins soggy, and in our initial tests frozen berries—which began to thaw—stained the batter an unappealing blue. Keeping the berries frozen until the last second helped.
• Tossing the blueberries with flour before adding them to the batter prevented the berries from sinking to the bottom of the muffins.
• For a simple streusel that didn’t distract from the flavor of the muffins, tasters preferred a mixture of flour, butter, dark brown sugar, granulated sugar, and cinnamon.