Funfetti Bundt Cake

FUNFETTI CAKE:

 * 2 1/2 cups cake flour, sifted
 * 1 teaspoon baking powder
 * 1 teaspoon baking soda
 * 1/2 teaspoon salt
 * 1 1/4 cups granulated white sugar
 * 1 cup (2 sticks) unsalted butter, softened
 * 1/4 cup vegetable oil
 * 2 large eggs, at room temperature
 * 1 tablespoon vanilla extract
 * 1 cup buttermilk
 * 2 large egg whites, at room temperature
 * 1/2 cup rainbow sprinkles (see Recipe Notes below)
 * additional sprinkles for topping

WHITE CHOCOLATE GLAZE:

 * 8 ounces white chocolate, chopped
 * 1/3 cup half and half cream
 * 1/8 teaspoon salt
 * 1 to 1 1/2 cups powdered sugar, sifted

MAKE THE CAKE:

 * Preheat the oven to 350 degrees F.,  Spray a 10 to 12 cup bundt pan with nonstick spray.
 * In a medium bowl, whisk together flour, baking powder, baking soda and salt.
 * In a large bowl, use an electric mixer to combine the sugar, butter and oil at medium speed for 4 minutes or until light and fluffy.  Beat in whole eggs, one at a time.  Beat in the vanilla.
 * At low speed, beat in the flour mixture and buttermilk, making three additions of flour and two of buttermilk, and beating until incorporated.
 * In another medium glass or stainless steel bowl, using the handheld mixer and clean beaters, beat the egg whites on medium-low speed until foamy.  Gradually increase to high speed and beat until firm peaks form.
 * Using a spatula, carefully fold whites into batter in two additions. Fold in the sprinkles (see Recipe Notes below).  Transfer the batter to the prepared pan and smooth the top.
 * Bake in a preheated oven for 45 to 55 minutes or until a tester inserted in the center comes out clean.  Let cool in pan for 10 minutes, then carefully invert the cake onto a wire rack to cool completely.

PREPARE THE GLAZE:

 * In a small saucepan, stir together the white chocolate, cream and salt over medium-low heat until melted and smooth.  Whisk in 1 cup of the sugar.  Whisk in more sugar, if necessary, 2 tablespoons at a time, until the glaze is thick but pourable.
 * Pour the glaze over the cooled cake, letting it drip down the sides.  Decorate with plenty more sprinkles.  Let the glaze set for at least 20 minutes before serving.