Peel and finely grate the ginger. Mix flour, sugar, baking powder and ginger. Add egg and butter in pieces and knead everything into a smooth dough. Cover and chill for about 1 hour. Roll out the dough on a floured work surface to a thickness of about 5 mm. Cut or cut out the teapot. Line 2 baking trays with baking paper and place the pot on top.
Bake the trays one after the other in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for about 10 minutes. Let them cool down. Chop the couverture separately, melt carefully one after the other in a warm water bath. Spread the biscuits with it and decorate. Cut candied ginger into strips. Decorate biscuits with ginger strips and brittle. Leave to dry