Pre-heat oven 190°C

In a large bowl combine the self raising flour, baking powder and salt

Grate the Copha over the flour. Rub the Copha into the flour until mixture resembles fine breadcrumbs. Stir the grated cheese through

Make a well in the centre of the flour mixture and pour in 3/4 of the soda water and the beaten egg. Mix to a firm but tacky dough, adding more soda water if required

Turn dough out onto a lightly floured board and knead gently

Roll dough out to a long rectangle 40cm x 20cm

Spread the dough with the tomato paste or pesto, then top with the bacon and grated cheese. Roll dough up as per a sponge roll. Cut dough into thick even slices

Place pinwheels close together in a lightly floured non-stick 24cm baking cake tin

Sprinkle pinwheels with a little extra cheese and bake in the pre-heated oven at 190°C for 12-14 minutes

Cool on a wire rack and serve warm