Preheat oven to 190ºC Lightly grease a baking sheet. In a saucepan melt chocolate over low heat. Let cool. In a small bowl mix flour, baking powder and salt. In a medium bowl beat margarine and sugar until creamy. Stir in egg, vanilla and chocolate. Add flour mix and mix all well, forming a stiff dough. To make spiders, shape a 5 cm flat oval for the body. Make the spiders head by flattening a circle about 1 cm wide. Shape dough for 8 legs, each 5 cmes long and less than 1 cm wide. Attach the head and legs to the body. Use red candies for the eyes. Bake in 190ºC oven for 5-8 minutes. Let spiders cool on baking sheet to avoid breaking when removing.