In an electric mixer fitted with the paddle attachment, beat the butter and lard at medium speed for about 1 minute.
Gradually add the sugar and increase the speed to medium-high.
Occasionally stopping to scrape down the sides with a rubber spatula, continue to beat until the mixture is pale and fluffy. Stir in the vanilla extract and lemon zest.
In a large bowl, blend together the flour, spices and salt. Add to creamed butter mixture and stir with a wooden spoon or spatula.
Return the bowl to the stand and mix on the lowest speed until the flour is just incorporated. Do not over mix.
Turn out the dough onto a large piece of plastic wrap. Push together to form a large flat disc and wrap well. Refrigerate until very firm, for at least 2 hours or overnight.
Once chilled to firmness, slice. sprinkle with powdered sugar, and serve.