A treat for breakfast or tea that can be made year-round with fresh or frozen raspberries. The streusel ingredients make much more streusel than you will need so you can cut it down. I make it all and put the extra streusel in the freezer and then I have streusel whenever I need it. I usually just mix up the streusel in a bowl and work in the butter with my fingertips. I also only get 10 muffins out of this but I have a tendency to really fill up my muffin cups.