1. Heat oven to 350º. Grease and flour 12-cup fluted tube pan or 10-in. tube pan.
2. Combine cake mix, yogurt, eggs, milk, poppy seeds and lemon peel in large bowl; beat until well blended. Pour batter into prepared pan.
3. Bake 40 to 45 minutes or until wooden pick inserted in center comes out clean. Cool 20 minutes; remove from pan to wire rack. Cool completely.
4. Prepare Chocolate Citrus Glaze; spoon over cake, allow glaze to run down sides.
Chocolate Citrus Glaze:
1. Melt butter in small saucepan over medium heat.
2. Stir in cocoa, water, liqueur, and orange extract.
3. Whisk in powdered sugar until smooth. If glaze is too thin, whisk in additional 1/4 c. powdered sugar. Use immediately.