1) Move a rack to the middle of oven. Preheat oven to 325 degrees F. Butter and flour a kugelhopf or other 2-quart bundt plan. Set aside.
2) Whisk together flour, baking powder and salt in a bowl. Set aside.
3) Using paddle attachment, beat butter, granulated sugar and lemon zest in the bowl of an electric stand mixer at medium speed, until pale and fluffy, about 2 to 3 minutes. Add eggs one at a time, beating well after each additin. Beat in vanilla. Reduce mixer speed to low. In three batches beginning and ending with flour, add flour, alternately with milk and lemon juice, and beat just until combined