Adjust oven rack to middle position and preheat oven to 325°F. Spray a 10-inch Bundt or tube pan with nonstick baking spray. Set aside.
In a large bowl, whisk the flour, baking powder, and salt together; set aside.
2 cups all-purpose flour, 1 teaspoon baking powder, 1 teaspoon kosher salt
In the bowl of a stand mixer fitted with the paddle attachment, cream the granulated sugar, butter, and cream cheese together on HIGH until light and fluffy, about 3 minutes.
1⅔ cups granulated sugar, 6 tablespoons unsalted butter, 8 ounces cream cheese
Add the eggs, one at a time, beating on MEDIUM until incorporated after each addition.
2 large eggs
Add the oil, zest, grapefruit juice and vanilla; beat until incorporated.
¼ cup canola oil, 2 tablespoons pink grapefruit zest, ¼ cup fresh pink grapefruit juice, ½ teaspoon pure vanilla extract
Alternately, beginning and ending with the milk, add the flour mixture and the milk. Beat just until incorporated after each addition.
¼ cup whole milk
Pour the batter into the prepared pan.
Bake at 325°F for 60-70 minutes or until a toothpick inserted in the center comes out with just a few crumbs.
Transfer the cake to a cooling rack, cool 10 minutes then invert cake onto the rack – turn cake upright. Cool completely.
While the cake cools, prepare the Ginger Grapefruit Glaze: In a medium bowl, whisk together juice, zest, oil, ginger paste, and salt. Add powdered sugar and whisk until creamy and smooth.
½ cup fresh grapefruit juice, 1 tablespoon pink grapefruit zest, 2 tablespoons canola oil, 1 teaspoon ginger paste, ⅛ teaspoon kosher salt, 4 cups powdered sugar
Drizzle the cooled cake with glaze and sprinkle evenly with the crystallized ginger.
¼-½ cup candied ginger