Pre-heat your oven to 160C Fan/350F/Gas Mark 4 and grease two 6-hole donut tins (or one 12-hole tin) with the butter
Put the self raising flour, caster sugar and cocoa powder into a mixing bowl and stir together
In a large jug, or another mixing bowl, whisk together the milk, vegetable oil, orange extract and eggs
Pour the milk mixture into the flour mixture, and whisk gently to combine into a batter
Divide the batter between the trays. You can put the batter into a piping bag or a jug to make it a bit neater to dispense into the trays, but you can do it with a spoon too
Bake them for 12 minutes, then remove them from the tin (I use a spoon to prise them out) and leave to cool on a rack
Make the ganache by putting the double cream, dark chocolate and butter into a microwave safe bowl. Blast it on high for 20 seconds, then stir. Blast in 10 second goes, sittring between each one, until it is smooth and glossy. You can also use a bain marie. Then add the orange extract and stir in
Set the donuts onto a rack or directly onto some baking paper. Dip the more rounded side of them into the ganache, then place back onto the paper/rack
Melt the white chocolate, then add the orange food colouring until a bright orange shade is achieved. Pipe or drizzle it over the donuts, then stick on a Terry's Chocolate Orange segment while the glaze is still wet. You can add sprinkles too if you like. Leave to set, or dig straight in!
Store leftover in an airtight container and eat within 3-4 days