Preheat the oven to 350°F (175°C). Spray a bundt pan thoroughly with nonstick cooking spray (use a spray that contains flour for best results).

In a medium bowl, whisk together 3 cups (372 g) all-purpose flour, 1 teaspoon baking powder, and 1 teaspoon salt. Set aside.

In a large bowl, use an electric mixer to cream 1 cup (226 g) softened unsalted butter and 2 cups (400 g) granulated sugar on medium speed until light and fluffy, about 3–5 minutes. Scrape down the bowl as needed.

With the mixer on low, add 5 large eggs one at a time, beating well and scraping the bowl after each addition.

In a measuring cup or small bowl, combine 3/4 cup (177 ml) buttermilk, 1/3 cup (79 ml) fresh orange juice, 2 tablespoons orange zest, 1 teaspoon vanilla, and 1/2 teaspoon orange extract (if using).

With the mixer on low speed, add the flour mixture to the batter in three additions, alternating with the buttermilk mixture: flour — buttermilk — flour — buttermilk — flour. Begin and end with the flour. Mix only until each addition is just incorporated; do not overmix.

Pour the batter into the prepared bundt pan and smooth the top with a spatula. Bake until a toothpick inserted into the center comes out clean or with a few moist crumbs, 45–55 minutes. Rotate the pan once halfway through baking if your oven has hot spots.

While the cake bakes, make the warm orange glaze: combine 1/4 cup (50 g) granulated sugar and 1/4 cup (60 ml) fresh orange juice in a small saucepan. Heat over low, stirring until the sugar dissolves and the mixture comes to a gentle simmer. Remove from heat and set aside to cool slightly; it will thicken as it cools.

When the cake is done, remove it from the oven and let it cool in the pan for 10 minutes.

After 10 minutes, invert the cake onto a wire rack set over a sheet pan or tray to catch drips. Use a pastry brush to brush the warm orange glaze evenly over the top and sides of the warm cake. Allow the glazed cake to cool completely on the rack before adding the drizzle.

Make the powdered sugar drizzle: in a small bowl, whisk 1 cup (113 g) powdered sugar with 1–2 tablespoons (15–30 ml) fresh orange juice (start with 1 tablespoon and add up to 2 for desired consistency) and 1 tablespoon orange zest until smooth. The drizzle should be thick but pourable.

Place the cake back on the wire rack and drizzle the powdered sugar mixture over the cooled, glazed cake. Let the drizzle set and dry, about 30 minutes.

Carefully transfer the cake to a serving plate. Store loosely covered at room temperature for up to 3 days.