Blueberry muffins with cinnamon crumble

Today's new culinary pursuit: blueberry muffins. David somewhat meaningfully informed me that his favourite kind of muffins is blueberry. <nudge nudge> So I consulted my mother for a recipe, as I recalled thoroughly enjoying her blueberry muffins. I was a little wary of attempting a crumble-top muffin again, as my last attempt hadn't been terribly successful. This recipe was also slightly more involved than say the super-easy banana muffins that essentially entail throwing everything into a food processor and pressing 'Go'. There are hand-mixers involved, creaming butter and alternating liquid and dry stuff, etc. But, blueberry bravery!I mixed together 2 cups flour (recipe actually calls for 1-1/2 cup regular flour and 1/2 cup of cake flour, but I don't have the latter), 1 tsp baking soda, 1/2 tsp baking powder, 1/2 tsp salt, 3/4 tsp cinnamon and 1/2 tsp nutmeg. In theory, I'm supposed to "sift" these together, but alas, I don't possess a sifter either (my baking supplies are somewhat lacking). In a separate bowl, 1/2 cup of room-temp butter and 1 cup of sugar were beat with a hand mixer until light and fluffy. 2 eggs (one at a time) were beaten in, and then 1-1/2 tsp vanilla extract. At low speed, I alternated adding the flour mixture and 1 cup of buttermilk (beginning and ending with flour mixture). Finally, I folded in a cup of frozen blueberries. For the crumb, I combined 1/2 cup of flour, 1/4 cup packed brown sugar, 1/2 tsp cinnamon and a scant 1/4 cup of butter, working it in my fingers to make a moist, crumbly mixture. Muffin mixture was spooned into the awaiting cups, and the crumb sprinkled on top (though perhaps not as liberally as I could have). I was still left with probably at least 2-3 muffins worth of muffin mixture, of which David happily ate several spoonfuls. They baked for approximately 25 minutes at 350 F. My crumble didn't melt into itself (hooray!), though, amusingly, the blueberries all sort of sank to the bottom of their respective muffins. David didn't seem to mind though. Success!NOTE: 04.15.11 - Email correspondence with my mother revealed how to rectify the sinking blueberries. Wash off any ice crystals on the frozen blueberries, pat dry and then lightly dust with flour.