1. Pre-heat the oven at 180°C and line a muffin tray.
2. Separately mix the dry and wet ingredients in two bowls.
3. Then incorporate them together, folding gently to have a soft batter. (Add a little more milk if necessary).
4. Divide into the muffin cases — Bake for around 30 minutes. Leave to cool.
5. In a standing mixer with cream beaters attached, beat the butter, adding the sugar little by little until you have a fluffy, light-coloured buttercream.
6. In a cup, mix the coffee extract and Lyle's Golden Syrup and a teaspoon of the buttercream. Then, incorporate the rest of the coffee syrup sauce in the icing. Don't overmix it, so that it remains marbled.
7. Place the nuts and Lyle’s Golden Syrup into a pan. Cook on high heat until the mixture becomes a little darker. Pour it onto baking paper to cool, then break into pieces.
8. To assemble, pipe the marbled coffee buttercream on top of the pumpkin muffins and top with the soft nut brittle.