• Softened butter for greasing the pan

• 1 package (18.25 ounces) plain white cake mix

• 1/2 cup finely chopped macadamia nuts

• 4 tablespoons (1/2 stick) butter, melted

• 4 large eggs, at room temperature

• 6 ounces white chocolate, chopped

• 2 packages (8 ounces each) cream cheese, at room temperature

• 1 can (14 ounces) sweetened condensed milk

• 2 small ripe bananas, peeled and mashed (about 3/4 cup)

• 1/2 teaspoon pure vanilla extract

1. Place a rack in the center of the oven and preheat the oven to 325 degrees F. Lightly grease a 13- by 9-inch pan with softened butter. Set the pan aside.
2. Measure out 1/2 cup of the cake mix and set it aside for the filling.
3. Place the remaining cake mix, the macadamias, the melted butter, and 1 egg in a large mixing bowl. Blend with an electric mixer on low speed for 2 minutes. Stop the machine and scrape down the sides of the bowl with a rubber spatula. The batter should come together into a ball. With your fingertips, pat the batter evenly over the bottom and 1 inch up the sides of the prepared pan, spreading it out with your fingers until smooth. Set the pan aside.
4. Place the white chocolate in a small glass bowl and heat in the microwave oven on high power for 1 minute. Remove the bowl from the oven and stir with a small rubber spatula until it is melted. (See Melting White Chocolate, page 92.) Let it cool slightly.
5. Place the melted white chocolate, cream cheese, and sweetened condensed milk in the same mixing bowl that was used for the crust. With the same beaters (no need to clean them either), blend with an electric mixer on low speed until just combined, 30 seconds. Stop the machine and add the reserved cake mix, the remaining 3 eggs, the mashed bananas, and the vanilla. Beat on medium speed for 1 minute. Stop the machine and scrape down the sides of the bowl with the rubber spatula. Pour the filling onto the crust, and spread it out with the rubber spatula so that it covers the entire surface and reaches the sides of the pan. Place the pan in the oven.
6. Bake the cheesecake until it looks shiny and golden brown and the center no longer jiggles when you shake the pan, 45 to 50 minutes. Remove the pan from the oven and place it on a wire rack to cool for 30 minutes. Lightly cover the pan with plastic wrap and place it in the refrigerator to chill for at least 1 hour, or preferably 24 hours, for the flavors to meld. Cut into squares and serve.

** Store this cake, covered first in plastic wrap and then in aluminum foil, in the refrigerator for up to 1 week. Or freeze it, wrapped in foil, for up to 2 months. Thaw the cake overnight in the refrigerator before serving.