Double Berry Crumb Muffins

This recipe comes from the Tate's Bake Shop Cookbook. I adapted this recipe in two ways-- since fresh berries are out of season, I used frozen without any problems. Since I freeze olallieberies (I live in California), I substituted those instead of blackberries and raspberries. The muffins were very moist and not too sweet. The crunch of the pecan streusel with a touch of fresh orange zest has made these muffins my new favorites. I also doubled the recipe and make one beautiful tea loaf.