Preheat oven to 350 degrees. Spray a 10-cup Bundt cake pan with a non-stick spray. Set aside.
In a large mixing bowl, using an electric hand mixer or in the bowl of a stand mixer fitted with a paddle attachment, beat the sugar and softened butter together until light and fluffy.
2 cups granulated sugar, 1 cup (2 sticks) unsalted butter
One at a time, add in the eggs and mix after each one. Add in the vanilla extract, mix until combined.
4 large eggs, 2 teaspoons vanilla extract
In separate large bowl, whisk together the flour, baking powder, and salt.
3 cups all-purpose flour, 1 ½ teaspoons baking powder, ¼ teaspoon kosher salt
Add part of the flour mixture into the wet mixture and mix until just combined, Add some of the milk and mix again. Repeat until both the flour and milk have been added in and well combined. 1 cup milk
Scoop out 2 cups of batter into a separate bowl. Add the Nesquik powder and Nutella to the 2 cups of batter and mix until well combined.
1/3 cup Nesquik chocolate powder, 2 tablespoons Nutella
Using a large spoon or cookie scoop, drop big dollops of each batter into the prepared Bundt pan, alternating where the colors land to create separation of the two.
Use a knife or skewer to gently swirl through the batter to create a swirly pattern through the cake.
Bake for 50-60 minutes, just until a toothpick inserted into the center comes out clean. Cool for 10 minutes in the pan and then invert the cake onto a cooling rack to finish cooling. Combine the sweetened condensed milk and chocolate chips into a small saucepan. Place the saucepan over medium heat and continuously mix until the chocolate chips are melted. Remove from the heat and mix in the vanilla extract. 1 14-ounce can sweetened condensed milk, 1 cup semi-sweet chocolate chips, 1 teaspoon vanilla extract
Place the cake onto a cooling rack that is sitting on top of a cookie sheet. For easy cleanup, line the cookie sheet with foil or parchment paper. Pour the glaze all over the top of the Bundt cake and allow it to drip down the sides. Go heavy with the pour and get a nice coating all over the cake. Allow the glaze to set a little bit before cutting, it won’t harden up solid but it will harden up enough to cut into it without dripping.