Preparation Preheat oven to 350°F. Butter and flour Bundt pan; set aside. Whisk baking powder, salt, and 3 cups flour in a medium bowl. Combine sugar and lemon zest in a large bowl; using your fingertips, rub together until lemon sugar is well blended. Add 1 cup butter to lemon sugar. Using an electric mixer on high speed, beat until mixture is light and fluffy, about 4 minutes. Add eggs one at a time, beating to blend between additions and occasionally scraping down sides and bottom of bowl with a rubber spatula, until mixture is light and very fluffy, about 4 minutes longer. Reduce speed to low. Add dry ingredients in 3 additions, alternating with buttermilk in 2 additions, beginning and ending with dry ingredients. Scrape batter into prepared pan; smooth top. Bake cake until golden brown and beginning to pull away from sides of pan, 60-70 minutes. Transfer to a wire rack and let cake cool in pan for 10 minutes. Invert cake onto rack; remove pan and let cool completely. DO AHEAD: Cake can be made 2 days ahead. Store airtight at room temperature. Combine preserves and lemon juice in a small saucepan. Bring to a boil, reduce heat, and simmer, stirring occasionally, until glaze is reduced to 1/2 cup, 6-8 minutes. Strain glaze into a small pitcher or bowl; discard solids in strainer. Pour glaze over cooled cake and let sit for at least 10 minutes.