Preheat the oven to 180C/160C fan/Gas 4. Line muffin trays with paper muffin cases. Cut the dried dates into raisin-sized pieces and the apple into 5mm pieces.
Beat the butter and sugar until soft and creamy. Add in the eggs, one at a time, mixing well between each addition and adding 1tbsp flour with the last egg. Sift in the rest of the flour and cinnamon, then stir in the fruit until just evenly mixed.
Divide between the cases and bake for 25 minutes or until the tops spring back when lightly pressed. Cool on a wire rack.