Step 1

Preheat oven to 350F with rack on lower middle position. Grease a standard bundt pan and set aside.

Step 2

In a large bowl, use a hand whisk to thoroughly combine the flour, baking powder, baking soda, and salt. Set aside.

Step 3

In bowl of stand mixer fitted with paddle attachment, cream the butter and 2 cups of granulated sugar on medium speed, 5 min or until light and fluffy. Beat in eggs one at a time until each is combined. Add orange zest, beating just until well incorporated; scrape down sides as needed.

Step 4

In a bowl, combine 1/4 cup of fresh orange juice, buttermilk, and vanilla extract. Gently fold buttermilk half of buttermilk mixture into the egg mixture, followed by half of the flour mixture; repeat with other half of buttermilk and flour mixtures, until all batter is gently folded together. Batter should be just combined but not over mixed; be sure to fold by hand with rubber spatula.

Step 5

Scrape all of batter into greased bundt pan and smooth top evenly. Bake 40-43 min or just until toothpick inserted in center comes out almost clean, with few tender crumbs attached. Let cake cool at least 15-30 minutes before removing.

Step 6

While the cake is baking, heat remaining 1/2 cup sugar with remaining 1/2 cup orange juice in microwaveable bowl and microwave 1 min or so, until sugar dissolves. Gently remove cake from bundt pan and invert onto a serving plate (I use a super sharp knife to gently loosen sides, before inverting. Then I give the pan a few strong pats, upside down, to pop the cake out.) Slowly drizzle sugar/orange mixture over cake and allow entire cake to cool completely.

Step 7

For Orange Glaze Topping: combine glaze ingredients and whisk until smooth (if needed, add another drop or two of orange juice for desired consistency.) Drizzle over top of cake. Finished cake can be kept airtight at moderate room temp for 1-2 days.