Cranberry crumble muffins

I'm sure it's everyone's 'using up leftovers' time this week, and I'd bought some cranberries and not used them. We love muffins and just to make them a bit different, I added some crumble mix on the top. I saw a chef doing this on one of the food programmes. They called it 'streusel topping' and I don't know if it's different from the run-of-the-mill crumble topping?
I used my usual muffin recipe and added the cranberries and some mixed spice.
This is my tried and tested muffin recipe, gathered from a friend in the US.

I'm not sure why, but I seem to make a different number of muffins each time I use the recipe! Today I made 11.

225g plain flour
100g caster sugar]
2 tspns baking powder
1 heaped tspn mixed spice

1/2 tspn salt
1 egg
250ml milk
120ml sunflower oil [ I usually use rapeseed, but only had sunflower left ]

Preheat oven 200C/400F/gas6

Either grease a muffin tin or put paper cases into the holes.

Mix the dry ingredients together in a bowl.
Mix the milk, egg and oil together in a jug then add to the dry ingredients - just stir it gently and don't overmix.
Spoon the mixture into the cases or into the tin filling them nearly full.
For the topping I used 50g plain flour and 25g butter rubbed together and 1 tbspn of soft brown sugar added to the mixture. I then sprinkled a little on top of each muffin.
Bake for 15-20 mins till golden.
Cool on a wire rack.

A very Happy New Year. xx

ps My lovely dil bought me a cake stand as one of my Christmas pressies. I love it.