Preheat oven to 350℉. Grease and flour a 10-in. fluted or plain tube pan.
In a large bowl, cream butter and sugar until light and fluffy. Add eggs, one at a time, beating well after each addition. Beat in lemon juice and vanilla. Add flour alternately with 7-Up, beating well after each addition.
Transfer batter to prepared pan. Bake 65-75 minutes or until a toothpick inserted in center comes out clean. Cool in pan 20 minutes before removing to a wire rack to cool completely.
For glaze, in a small bowl, mix confectioners' sugar and enough 7-Up to reach desired consistency. If desired, stir in lemon peel. Drizzle over cake.