Heat the oven to 180C. Line 2 large baking trays with baking paper.
Beat the butter and brown sugar until creamy. Add the egg and beat until well combined. Add the honey and golden syrup and beat until combined.
Sift the flour and baking powder over the butter mixture and fold in with the coconut.
Place teaspoonfuls of the mixture onto a prepared tray, placing slightly apart. The mixture is sticky. Using floured hands roll into balls then using a fork dipped in flour, press to flatten a little.
Place this first tray in the oven and bake for 10-12 minutes until the biscuits are a light brown. Remove from the oven and place biscuits on a wire rack to cool. Repeat with remaining mixture.
Make the buttercream filling, beat together the butter, icing sugar, vanilla paste until light and fluffy. Add a dash of milk if needed to soften.
To sandwich together, place some buttercream on the base of a biscuit and some jam on another and sandwich together. Repeat with remaining biscuits.
Keep stored in an airtight container for up to a week.