Cream the butter and sugar in a large bowl, using a hand held mixer till well blended. Mix in the spices. Mix the baking soda with the boiling water and add it to the dough along with the flour. Mix well into a stiff dough. If necessary add more water, a tablespoon at a time to get to the required consistency of dough. If using the cocoa powder, divide the dough into two portions. Chill the dough for at least 4 hours or overnight.

Draw the patterns for the row houses on cardboard using these templates, and then cut them out.

Take the dough out and leave it on the counter top for some time so that it softens up a little and becomes easier to work with. Divide the dough into two or three portions and work on one portion at a time. Roll out the dough on a floured work surface to about 1/8" thickness. Place the cardboard templates on the dough and cut around them with a sharp knife.

Transfer the cut out shapes to lightly greased or parchment lined baking sheets. Repeat with the remaining dough. Gather together the scraps, roll out and cut as many shapes as possible out of them.

Bake the cut outs at 190C (375F) for 15 to 20 minutes until the dough feels firm to touch. Leave them to cool on the baking sheet and they will become harder. When theyu2019re completely cool, decorate them with Royal icing.

To make the Royal Icing, beat all ingredients until smooth, adding the powdered sugar gradually to get the desired consistency. If not using the Icing immediately, keep it in a small bowl, loosely covered with a damp towel for a few hours until ready to use. Otherwise transfer to an airtight plastic container, place clingfilm over the surface to prevent crusting and cover. Refrigerate.

If it does crust slightly, beat it slightly to get it an even consistency. This Icing should keep in the fridge for 4 to 5 days.