Preheat the oven to 180C / 350F / 160C fan forced.
For the cheesecake filling
Beat together the cream cheese and sugar until smooth and creamy. 2-3 minutes should do it. Add the egg and beat well. Add the vanilla and sour cream and mix through until incorporated. Set aside.
For the chocolate bundt cake
In a large bowl sift together the flour, cocoa, baking powder, baking soda and salt. Add the sugar and chocolate chips and mix it well.
In a separate bowl whisk together the eggs, milk and vegetable oil until well mixed. Pour the wet ingredients into the dry and mix until just combined.
Lightly spray a bundt tin with spray oil, then tip 2/3 of the cake batter in. Spread evenly around the base. Now spoon in the cheesecake mixture just around the middle of the cake batter (ie not to the edges of the tin - keep it to a 1-2 inch line around the middle of all the cake batter). Top with the remaining cake batter, making sure to cover all of the cheesecake filling.
Bake for around 45 minutes, turning the tin half way through, until a toothpick inserted comes out clean (you'll have to test a couple of spots to make sure you're hitting cake and not choc chips)
Let the cake cool in the tin then transfer to a cake plate
For the dark chocolate ganache
Finely chop the chocolate, place in a bowl and set aside.
Heat the cream over low heat, swirling the pan every so often until it starts to simmer. Pour the warm cream over the chocolate then let it sit for 5 minutes (very important) before stirring to a smooth ganache.
Immediately, pour the ganache over the cooled cake. Give the cake a gentle shake and tap the plate gently on the bench top (a tea towel set down first will soften the blow a little) to smooth out the ganache. Serve immediately if you don't mind a gooey ganache or allow it to set before serving.
For best results you should always weigh ingredients like flour and sugar. Kitchen scales like these are relatively cheap but if you can’t weigh the ingredients, use the spoon and level method (don’t scoop).
I use this tin for my chocolate bundt cake. If you have a good quality non-stick bundt tin, then a simple spray of oil (make sure it's a brand that won't damage the non-stick surface) all around the inside right before you pour in the batter is all you need. If your tin is a little older then the best method is to grease it really well and then flour then inside as well.