Preheat the oven to fan assisted 160C / 180C / 350F / gas 4 and line a 12 cup muffin tray with paper cases.
In a large bowl, mix the flour, baking powder, signature spice and salt.
In a separate bowl whisk together the oil, milk, egg, orange juice and sugar.
Add the wet ingredients into the dry and mix until just combined, then quickly fold in the nutty granola.
Divide the muffin batter equally into the muffin cases
Make the cashew cranberry streusel topping by mixing all the ingredients together in a bowl and diving the topping evenly over the muffins and finishing with a sprinkle of the signature spice.
Bake in the oven for 22 mins or until a skewer inserted into a muffin comes out clean.
Allow the muffins to cool slightly in the baking tin before transferring them a rack to cool completely.