Combine the flour, baking powder, nutmeg, cinnamon, and salt in a bowl.
In another bowl, beat the eggs until light and frothy. Add the sugar and whisk to dissolve. Add the butter and vanilla and continue to whisk for 2 to 3 minutes. Add the flour mixture, about 1 cup at a time, blending together until a stiff dough forms.
Lightly flour a work surface and sprinkle the dough with a little flour. Pat the dough into a large rectangle, about 1/8 inch thick. Using a pastry wheel or a sharp knife, cut out about 12 diamond-shape pieces. Make a slit lengthwise through the center of each diamond.
Heat the shortening to 360ºF. in a deep-fryer or deep saucepan. Deep-fry the diamonds, two to three at a time, turning them around with a slotted spoon, until they are golden brown and crisp, about 4 minutes. Transfer to paper towels to drain.
Dust with powdered sugar and serve immediately.
Yield: 1 dozen, 6 servings