Preheat oven to 180 degrees C. Grease and flour a ring tin. Sift together the flour, bicarb soda, salt cinnamon, nutmeg, allspice and ginger. Set aside.
In a large bowl, cream together the shortening, eggs, brown sugar and white sugar until light and fluffy. Beat in the pumpkin puree. Beat in the flour mixture. Stir in the chopped pecans. Pour batter into prepared tin.
Bake in the preheated oven for 60 to 65 minutes, or until a toothpick inserted into the centre of the cake comes out clean. Let cool in tin for 10 minutes, then turn out onto a wire rack and cool completely.