In a large bowl, cream together the butter and syrup until creamy.
Add the rest of the ingredients (except for the jam and icing sugar) and beat until you have a crumbly dough. It will look like crumbly peas when beating, but it will come together as a dough.
Form dough into a ball, wrap in clingfilm and chill for at least a couple of hours.
Preheat oven to 170c.
Line two baking sheets with greaseproof paper.
Separate your dough into two balls. Clingfilm one ball and return to the fridge.
Roll out the other ball on a floured work surface, until it's about ½cm thick.
Using your Linzer Cookie Cutters, cut out equal amounts of top and bottom cookies. Place on baking sheet.
Bake for 8 minutes or until very pale golden. Let cool for a couple of minutes on the baking sheet, then let cool completely on a cooling rack.
Place half a teaspoonful of jam onto the bottom cookies.
Dredge the tops with icing sugar, then sandwich to a jammy bottom!