Preheat an oven to 190 degrees C. Combine flour, bicarb soda, baking powder, cinnamon, cloves and salt in a bowl. Set aside.
Beat the butter and sugar with an electric mixer in a large bowl until smooth. Beat the egg into the butter until completely blended, then stir in the rhubarb. Mix in the flour mixture until just incorporated. Fold in the raisins, nuts and linseeds, mixing just enough to evenly combine. Drop spoonfuls of the dough 5cm apart onto ungreased baking trays.
Bake in the preheated oven until lightly browned, 12 to 15 minutes. Cool on the trays for 10 minutes before removing to cool completely on a wire rack.