put the raspberries on a baking sheet and freeze until ready to use
make the streusel: mix together all the streusel ingredients until crumbly, put in the fridge to chill until ready to use
beat the butter and sugars together until soft and whipped, about 4 - 5 minutes
add the egg, vanilla, and lemon zest if using, and beat well
in a separate bowl mix the flour, soda, salt
stir into the wet ingredients
stir in the chocolate chips
and then add the semi-frozen raspberries
divide into 12 cookies and place on a baking sheet, topped with streusel
refrigerate 20 minutes
preheat the oven to 350° while the cookies chill
bake the chilled cookies for 10-12 minutes until they're just set, don't let them get too brown
cool for 5 minutes on the baking sheet and then transfer to a cooling rack