1.   Pre-heat the Oven The first step is heating your oven to 350 degrees F (175degC). Grease and dust a 9×13 inch baking pan to make sure it is that the cake is easy to remove after.

2.   Prepare the dry ingredients In a large bowl, mix together all-purpose flour baking powder, cocoa powder and salt. Put this mix aside.

3.   Cream the butter and sugar In a larger mixing bowl, mix together the softened vegetable oil and butter together with the white sugar until it is fluffy and light. This is essential since it helps to incorporate an airy texture into the batter allowing the cake to rise beautiful.

4.   Add the eggs and Zucchini Mix eggs one at a time, and mixing thoroughly following each addition. Mix in the zucchini, which not just provides moisture, but also an underlying sweetness.

5.   Combine Dry and Wet ingredients Mix the dry ingredients into the wet ingredient mixture, and alternate and mixing in the buttermilk. This helps preserve the cake’s softness.

6.   Make the Cream Cheese filling In a medium bowl, mix the smooth cream cheese with butter to make it they are smooth. Gradually add sugar and cornstarch and mix until blended. Then, add the milk, egg along with vanilla extract till it is well-blended and creamy.

7.   Layer the batter Layer the Batter: Pour half of chocolate batter in the baking pan and spread it evenly. Pour frosting of cream cheese over it, spreading equally. After that, pour the rest of the chocolate batter over it making sure not to scratch the layer of cream cheese.

8.   Bake: Place the cake pan in the oven preheated and bake for between 50 and 60 minutes. Determine if the cake is done by inserting a toothpick into its center. It should be clear or have some moist crumbs.

9.   Cool When the cake is baked and allowed to sit in the cake pan to cool for around 15 minutes before moving it onto a rack on wire to completely cool.