Preheat oven to 350 degrees (F).

Heavily grease a bundt pan with vegetable shortening (not butter) and sprinkle with granulated sugar.

In a large bowl whisk the cake mix and instant pudding mix together.

Add the lemon zest, sour cream, vegetable oil, eggs and sherry (or milk).

Using an electric mixer (either handheld or stand), beat until the batter is smooth, about 2 minutes.

Stir in the poppy seeds.

Pour cake batter into prepared baking pan and bake for 40 - 50 minutes, until a wooden skewer inserted comes out mostly clean. A few moist crumbs clinging is fine.

Allow to cool in the pan 10 minutes before inverting cake onto a serving platter.

Allow to cool completely before drizzling with glaze.

Whisk the powdered sugar and lemon juice together until smooth. If the mixture is too thick to drizzle, add lemon juice, 1/2 teaspoon at a time, until desired consistency is reached.

Drizzle glaze over completely cooled cake.

Store at room temperature, covered, for up to 3 days.