Preheat the oven to 325°F (165°C). Grease and flour a fluted tube pan, such as a Bundt pan.

In a bowl, sift together the flour, baking powder, and salt.

In a large bowl, combine the sugar and butter, then beat with an electric mixer until smooth and creamy. Add the eggs one at a time, beating well after each addition. Gradually add the flour mixture in three parts, alternating with the sour cream, and briefly beat the batter after each addition. Stir in the lemon zest and pour the batter into the prepared pan.

Bake in the preheated oven for 55 to 60 minutes, or until a toothpick inserted into the center comes out clean. Cool the cake on a wire rack for 5 minutes. Run a table knife around the edges to loosen it, then carefully invert the cake onto a serving plate or cooling rack. Let it cool completely, about 1 hour.

In a small bowl, stir together 3 teaspoons of lemon juice, powdered sugar, and melted butter until a thick glaze forms. Drizzle the glaze over the cooled cake.