Step 1Heat the oven to 325 degrees. Butter and flour a 10-inch tube pan. Set aside.
Step 2Combine the poppy seeds, honey and water in a saucepan and cook over low heat until the water evaporates, stirring frequently, 4 to 5 minutes. Cool.
Step 3Cream together the butter, sugar, lemon zest and vanilla. Add the eggs, 1 at a time, beating well after each addition. Add the sour cream, poppy seed mixture, salt and lemon juice at low speed, combining thoroughly.
Step 4Sift together the flour, baking soda and baking powder. Add the flour mixture to the poppy seed mixture. Beat at low speed until thoroughly combined.
Step 5Pour the batter into the pan. Bake until the cake draws away from the sides of the pan and a toothpick inserted in the center comes out clean, 50 to 60 minutes. Cover with foil if the cake browns too quickly. Remove the cake from the pan and cool to lukewarm.
Step 1Combine the lemon juice and powdered sugar in a saucepan. Bring to boil and cook until a thin syrup is formed, 1 to 2 minutes. Brush the glaze over the lukewarm cake.