In a small saucepan add the milk and butter, and cook over low heat until butter is melt. Put aside to cool slightly.
Sift the 500 g of flour, mixed spice, cinnamon, and nutmeg into a large bowl
Add the brown sugar, salt, and instant yeast then mix with a wooden spoon to combine.
Add the milk and melted butter. Whisk the egg and add to the mixture, and mix until well combined.
Once combined, using the dough hook, turn your stand mixer onto a medium-high speed and kneed for 5 minutes.
Turn the dough out onto a lightly floured surface. Slowly add the extra ¼ cup of flour, a little at a time, and knead lightly until flour is incorporated. Continue to do this till the dough is no longer sticky.
Grease a ball with olive oil and place the dough in the bowl, cover with cling wrap and a towel, and place in a warm area to prove for one hour or until doubled in size.
Preheat your oven to 200°C or 390°F
Remove the dough and roll out into a long roll. Cut into 12 equal parts. Create a ball out of each potion and place it in a well-greased rectangle baking pan. Cover loosely with cling wrap and a towel and let it prove for one hour or until buns have doubled in size.