Preheat oven to 350°F.
Lightly butter a 9×13-inch baking pan.
Cream butter, sugar and pumpkin pie spice until light and fluffy. Add eggs, beating well after each addition.
Combine flour, baking soda and salt; add to the butter alternating with addition of pumpkin and lemon juice. Stir in pecans.
Spread batter evenly into prepared baking pan and bake 30-35 minutes (or until wooden skewer inserted in center comes out clean.)
Allow the cake to cool. Spread frosting on cake and garnish with candied ginger.
Cream butter with pumpkin pie spice and lemon zest. Blend in cream cheese.
Add confectioners sugar and ¼ cup pumpkin; beat until smooth.