1.Heat oven to 350°F Butter a 12-cup bundt pan.
2.In a large bowl, whisk together flour, baking powder, baking soda, salt, and the 1/4 cup poppy seeds. Set aside.
3.In another large bowl, beat butter (or margarine) until smooth. Add sugar and beat for 2 to 3 minutes until fluffy. Beat in eggs, one at a time, beating well after each addition. Add lemon juice, lemon zest and vanilla and beat until combined. Beat in flour in three additions, alternating with yogurt. Beat for 2 minutes. Spoon into prepared pan.
4.Bake at 350F for 50 minutes or until a toothpick inserted in center of cake comes out clean. Cool on a wire rack for 20 minutes. Run a sharp knife around edges of the pan. Turn out and cool completely.
5.Glaze1 cook glaze 1 ingredients together in small pan unitl syrupy. Pour over cooling cake to soak in,.
6.Glaze 2: in a small bowl, mix together confectioners' sugar, lemon juice until smooth. Drizzle over top of cake and let it roll down the sides. Decorate with lemon zest or poppy seeds.