1. Preheat oven to 350 degrees F (175 degrees C). Grease and flour a 10 inch Bundt pan.
2. In a large bowl, cream together the butter, shortening and sugar until light and fluffy. Add the eggs one at a time, beating very well after each. Stir in the lemon extract and vanilla. Beat in the flour alternately with the milk, mixing just until incorporated.
3. Pour batter into prepared pan. Bake in the preheated oven for 60 to 75 minutes, or until a toothpick inserted into the center of the cake comes out clean. Allow to cool, then drizzle with lemon glaze.
4. To make the lemon glaze: Put the confectioners' sugar into a small bowl. Mix in lemon juice, a teaspoon at a time, until desired drizzling consistency is achieved.