Pre-heat your oven to 160C Fan/350F/Gas Mark 4, grease and line two 8" cake tins (that are at least 2" deep)
For the sponge, mix together the butter and the caster sugar in a large bowl until fluffy, ideally using an electric mixer
Add the eggs and vanilla extract, and mix in well
Add the self raising flour and mixed spice, and gently mix in until you can't see any flour anymore
Divide the mixture between the tins, use scales for accuracy if you like
Bake them for 30-35 minutes or until a skewer inserted in the middle comes out clean. Leave them to fully cool either in the tins or on cooling racks
If the cakes have domed on top, level them off with a cake leveller or knife
To make the buttercream mix the butter on it's own until it's smooth and creamy, for 2-3 minutes. Use an electric whisk or stand mixer with the paddle attachment for best results. Add the icing sugar and brandy. Mix until smooth. If the buttercream is too stiff then you can add a little more brandy
Put one of the sponges on a cake stand or a serving plate, pipe buttercream all over the sponge, then spoon mincemeat over it. Add the final sponge and pipe larger rosettes around the edge and smaller ones in the centre. Fill the middle with mincemeat and decorate the edges with the mini mince pies
Leftovers will keep in an airtight container in a cool place for 2-3 days
Notes
Make sure all your ingredients (particularly the butter and eggs) are at room temperature before you start baking.
I used a baking spread for the cake and unsalted butter for the buttercream.
Mixed spice is a British spice blend containing cinnamon, coriander seed, nutmeg, clove, pimento, and ground ginger. If you can't get hold of it where you're based, you can use a Pumpkin Spice mix instead or add extra cinnamon, ginger, nutmeg and ground cloves.
I use shop bought mincemeat for this recipe, but feel free to use a homemade version.
Although I provide cup measurements, I highly recommend weighing your ingredients out using digital kitchen scales. It is the most accurate way to measure ingredients and will ensure the best results. Digital scales are very low cost and can be purchased for around £12 ($16.50) .
For teaspoon (tsp) and tablespoon (tbsp) measurements, please use measuring spoons and not the type of spoons you eat with. Again this will ensure accuracy and provide the best results.