Line a tube cake tin with baking parchment and brush with melted butter.
Cream butter and then beat in sugar. Beat in eggs one at a time, beating well after each addition. Stir in extract. Mix in flour, baking powder and salt. Stir in raisins, cherries, pineapple and mixed peel. Allow this to sit overnight in covered bowl.
Transfer to the prepared tin. Bake at 150 C / Gas 2 for 2 1/2 hours with a tin of hot water placed on the lowest rack of your oven during baking. Brush warm cake with some melted butter.