REMOVE the cream cheese from the refrigerator to soften and come to room temperature. It must be a soft, spreadable texture.
CHOP the Hershey milk chocolate bar into small pieces. Remember, you want the chocolate light enough to not sink. (Alternately use mini chocolate chips instead).
PREHEAT the oven to 350° F (175° C).
POUR the box of yellow cake mix and pudding mix into a large mixing bowl. Stir to distribute the two mixes.
BEAT the cream cheese in a separate bowl with an electric mixer on low speed. Make sure it is smooth and softened. Then mix in the buttermilk and oil. The mixture will not look completely smooth. Don’t worry about that.
ADD the wet ingredients to the dry ingredients. Beat with a hand mixer for 30 seconds on medium speed. Add the eggs and mix on low speed until combined.
INCREASE to medium speed and beat for 1½ minutes. The cake batter should be completely smooth, with no dry mix visible.
RESERVE 2 to 3 tablespoons of chopped chocolate. Fold the rest of the chocolate into the cake batter. Use a rubber spatula to mix and distribute the chocolate throughout the batter.
GREASE a 12-cup Bundt pan with Baker’s cooking spray (or any floured cooking spray for baking).
POUR batter into the greased cake pan. Place the pan on a baking sheet (optional). The baking sheet makes it easy to take the pan in and out of the oven. It also catches any spills.
PLACE the cake into the preheated oven.
BAKE for 50 to 60 minutes. The cake has finished baking when the sides pull away from the pan. The top will look toasty golden brown. And when you stick a toothpick in the center of the cake, it will come out clean.
REMOVE the pan from the oven and turn the oven off. Place the cake pan on a wire rack to get circulation under the pan and help it cool. Cool the cake IN THE PAN for 10 to 15 minutes.
TO REMOVE the cake from the pan, place a wire rack on top of the cake. Invert cake onto the wire rack. The pan should slip off easily.
COOL the cake to room temperature. When the cake is cool, wrap it in plastic wrap. Place it in an airtight container until you are ready to frost it.
Choose one of the Toppings
Milk Chocolate Ganache
CHOP the chocolate and place it into a small bowl.
WARM the cream over low heat.
WHEN the cream is steamy (but not boiling), pour it on top of the chocolate.
COVER the bowl with a plate for 5 minutes. This keeps the heat in and helps the chocolate melt.
UNCOVER the bowl and whisk until the ganache is smooth.
COOL for a few minutes before pouring.
DRIZZLE the chocolate ganache on the cake.
OPTIONAL: Before the ganache sets, sprinkle crushed chocolate chip cookies, sprinkles, or chocolate chips on the cake.
Cream Cheese Frosting
SOFTEN the cream cheese.
ADD the cream cheese, butter, and vanilla extract to a large bowl. Beat with an electric mixer until creamy.
POUR in the powdered sugar and beat until smooth.
ADD the heavy cream (if needed) and mix until it is a spreadable consistency.
SPOON the cream cheese frosting into a piping bag with a large round decorating tip. (Or a zip-top bag with the corner tip cut off.) Starting on the outside of the cake, pipe a smooth line in the groove of the cake. End inside the bundt cake hole. Continue to pipe each line. Use an angled spatula or a knife to smooth the frosting in the center.
Brown Butter Glaze
MELT the unsalted butter in a small saucepan. Continue to heat over low heat as the butter browns. The milk solids will start to turn brown and smell toasty. Do not let it burn.
COOL it for a minute or two when the butter has browned. Then pour it into a medium mixing bowl. Add the powdered sugar and vanilla and mix with an electric hand mixer. Add the milk and mix until it is smooth and ready to drizzle.
POUR the glaze into a liquid measuring cup with a pour spout. Slowly pour the glaze onto the top of the bundt cake. Let it slide down the sides.
SERVE when the glaze cools and hardens.