Prep oven. Position a rack in the center of your oven and preheat to 350°F/177°C.
Combine dry ingredients. In a large bowl, sift together the flour, baking powder and baking soda. Stir in the salt. Set aside.
Combine sour cream, lemon and vanilla. In a second small bowl, stir together the sour cream, lemon juice, lemon zest and vanilla. Set aside.
Cream butter and sugar. In a large mixing bowl with an electric mixer (or a stand mixer fitted with paddle attachment), cream together the butter and sugar until light and fluffy, about 2 to 3 minutes on medium high speed.
Add eggs. Add the eggs one at a time, scraping down the mixing bowl well after each addition and mix until blended.
Alternate dry mixture and sour cream. Add the flour mixture and sour cream mixture alternately to butter-sugar-egg mixture, beginning and ending with the flour mixture until uniformly incorporated- do not overmix.
Bake. Grease and flour one 12-cup capacity bundt cake pan. (I like to use either shortening and flour or a cooking spray that includes flour). Pour batter into pan. Bake in a preheated 350°F degrees oven for approximately 50-55 minutes, until top is golden brown and when the cake is done when a toothpick or skewer inserted in the center comes out clean or with a few moist crumbs. Cool in the pan for 10 minutes, then invert on to a cooling rack (You may need to loosen around the edges of the cake before inverting).
Make glaze. In a small bowl, whisk together the glaze ingredients. Adjust consistency if needed. Pour over cooled cake before serving.