Preheat oven to 350ºF (180°C).
Grease a 10 or 12-cup bundt cake pan (26cm) with soft shortening, covering every angle, nook and cranny. Dust with flour, shaking off excess. Reserve.
Sift 2 ½ cups all-purpose flour, 2 ½ teaspoons baking powder and ½ teaspoons salt. Set aside.
Beat ¾ cup unsalted butter until creamy in a large bowl. Slowly add 1 ¾ cup sugar and beat for 2 minutes.
Add 3 eggs one at a time, beating well after each addition, and then beat for 2 more minutes.
Add 2 teaspoons ground fresh cardamom, ½ teaspoon vanilla extract and 1 teaspoon lemon zest if using it.
Beginning and ending with dry ingredients, add them in 3 parts alternating with ¾ cup whole milk and ½ cup sour cream in 2 parts.
Pour batter into prepared pan, spreading evenly.
Bake for about 45-50 minutes or until a cake tester or toothpick comes out clean. Depending on the type of pan and oven you use, it might take more. So always check and take baking times given in a recipe as a reference.
Let cool 5-10 minutes and carefully invert onto a wire rack.
Cool completely. Cover in plastic wrap until ready to serve.
Dust with powdered sugar before serving. Or use a glaze (see Notes below).