Heat the oven to 170C, 150C fan oven, gas mark 3. Lightly grease two baking sheets.
Draw simple egg or bunny-shaped templates out of stiff card.
Put the butter into a medium bowl. In a small pan, gently heat together the sugar, syrup, caramel, bicarbonate of soda and mixed spice, until smooth. Bring to the boil and pour over the butter. Stir until all the butter has melted.
Beat in the egg yolk and flour and knead lightly on a floured surface to a smooth dough. Roll out the dough to about the thickness of a pound coin.
Children will love to help with the rolling and cutting the dough into shapes around the cardboard stencils with a round-bladed knife.
Transfer to the baking sheets and bake for 10-12 minutes. Cool completely.
To decorate, roll out ready made fondant icing. Apply to biscuits and then lightly brush a pattern with water and apply sprinkles or snipped up sweeties etc.
Alternatively, make a simple icing by combining icing sugar with water. Add a touch of jam or marmalade to gently colour.
Be inventive with store cupboard ingredients like raisins, nuts, sprinkles, chocolate chips etc.
If you don't have Bicarbonate of soda, use baking powder, but halve the amount so the biscuits don't puff up too much in the oven.
If smaller children find the shapes difficult to cut out, they could roll into small balls and press down with a fork or even use an imprint of a clean toy - like Lego bricks - to make fun patterns and shapes.
The thinner the dough, the crisper the biscuits will bake. If possible, roll out the dough between sheets of non-stick baking parchment.
The biscuits will store for 2-3 weeks in an airtight container or for 1-2 months in the freezer.