In a bowl, whisk the flour, baking powder, baking soda, salt, brown sugar, nutmeg, and allspice.
Add in the margarine and rub it in with your fingertips until the mixture is mealy.
In a small bowl, stir the pumpkin puree and yogurt together until blended; add to the dry mixture, and stir until the dough is sticky, adding a little more yogurt if necessary.
Transfer the dough to a lightly floured work surface and knead about 8 times.
Pat out 1/2 inch thick and cut out rounds with a 2-inch biscuit cutter.
Pat the scrapes together and cut out more rounds.
Arrange the rounds on a baking sheet about 1 inch apart and bake in the upper third of the oven until golden, about 12 minutes.