Preheat the oven to 356°F (180 °C) and lay out two trays with baking paper. Stir the flour, cocoa, spices, salt and baking powder (optional) together. Beat the butter and brown sugar at medium speed with a mixer until it is fluffy and becomes a homogenized mixture (about 4 minutes).
Add the egg, molasses and grated fresh ginger. Stir well and add the flour mixture. Beat on low speed until everything is mixed well. Divide the dough into 2 parts, flatten them slightly and place them for 1 hour in the refrigerator. Roll out each one into a thin sheet (one by one). With shapes, cut the biscuits out.
Arrange them in the trays and leave them again for 20 minutes in the fridge. If while you're rolling out the dough it's too soft, put it back in the refrigerator. Put the biscuits to bake for about 10-13 minutes in the preheated oven. Allow to cool on a cooking grid.