For the cake, preheat the oven to 180C/350F/Gas 4.
Place the sultanas, lard, muscovado sugar, golden syrup and water into a saucepan and bring to the boil, stirring constantly. Remove from the heat and cool - ideally overnight.
Grease and line a small loaf tin with lard. Sift the flour, baking powder, bicarbonate of soda and spices into a large bowl. Mix the cooled fruit mixture into the dried ingredients along with the eggs, beating well to combine.
Tip the cake mixture into the prepared cake tin and level the top. Place in the oven to bake for 1-1¼ hours until the top is golden-brown and a skewer inserted into the centre comes out clean.
Cool in the tin for 30 minutes, before turning out and cooling completely on a wire rack.
For the black pepper strawberry jam, place the sugar, lemon zest and juice into a large pan and heat until the sugar has dissolved. Add the strawberries and black pepper, bring to the boil and cook for five minutes.
Turn off the heat and leave the jam to cool, before skimming off any froth. Spoon into sterilised jars (about 2-3 jars, depending on their size).
To serve, slice the cake and spread generously with some of the jam.