Method (streusel)

1. In a medium-sized bowl, stir together the flour, sugar and cocoa powder.
2. Add in the room temperature butter and use a fork to mix and claw the ingredients together until combined but still clumpy. Don’t over-mix or the streusel will become like a soft paste, simply toss together until mixture is clumpy, no longer dry, and the flour is completely combined. Set aside while you make the chocolate muffin mixture. Make the streusel the day before and store in the fridge in a sealed container.

Method (muffins)

1. Preheat the oven to 180°C fan and line two 6 cup cupcake tins with cupcake / muffin liners.
2. In a small bowl combine the flaxseed with the water, stir until a paste and set aside. This will turn thick and jelly like.
3. In a medium sized mixing bowl, sieve in the flour, cocoa powder, baking powder, arrowroot, xanthan gum and sugar. Mix to break up any lumps.
4. In a separate bowl, add in the yogurt, room temperature butter, milk and flaxseed. Mix to combine. Pour the wet into the dry and mix until just incorporated. Fold in the chopped hazelnuts. Don’t over-mix!
5. Using an ice-cream scoop or spoon, divide the mixture between the cases. Make sure the batter reaches the top of the liners.
6. Drizzle some of the ”Nutella” on top of the batter.
7. Sprinkle a good amount of the chocolate streusel on top of each muffin, making sure the tops are covered.
8. Place into the middle of the oven and bake for 12 minutes at 180°C fan. After 12 minutes, reduce the oven temperature to 160°C fan and bake for a further 16-18 minutes, or until the skewer / toothpick inserted into the middle of the muffins come out clean.
9. Remove from the oven and allow the muffins to cool in the tin.
10. Transfer some of the Vegan ‘Nutella’ into a piping bag, and once the muffins are cool, core the middle and fill with ‘Nutella’. You can even drizzle more over the top and finish with a sprinkle of chopped hazelnuts. 
11. Serve and enjoy!