In a small bowl, mix together streusel ingredients until crumbly and set aside.
Preheat oven to 400 degrees.
Line two standard muffin tins with paper liners.
In a large bowl, whisk together half & half, sugar, melted butter, eggs, extracts, and lemon zest.
Add flour and mix in until no white streaks remain; batter will be lumpy.
Gently fold in raspberries.
Portion batter into paper liners.
Sprinkle streusel on top.
Bake for 20-25 minutes, or until toothpick comes out clean.
Let cool in pans for 5 minutes before turning out onto a wire rack.