Preheat the oven to 180 degrees. Line and grease a springform tin (mine is 20cm)
Make sure your cream cheese is room temperature! If it isn't, you'll end up with a lumpy cheesecake. You can unwrap the cream cheese and heat it in microwave in 10 second intervals, but I don't have a microwave, so I just allow the time, and sit it on my oven to speed things up.
Place all the ingredients for the base in your food processor, and combine until it forms a ball. If it doesn't, add a little extra butter, or a teaspoon of ice cold water. Once it comes together (it needn't be wet, or a ball, you just need to be able to gather it up in your hand) pour it into the lined tin. Use your hands to press it out evenly into the tin, and then poke a few air holes in it with a fork. Cook for around 10 minutes, or until it has puffed up slightly and has coloured. Set it aside to cool.
Place a small saucepan, half filled with water, over a medium heat. On top of that, place a metal bowl, ensuring the bowl doesn't touch the water. Place the chocolate in the bowl, and allow to melt completely. Keep an eye on it - too long over the heat can ruin it. Once it has melted, add the peanut butter and salt, and stir to combine. Turn the heat off, and, depending on the weather where you are, either leave the chocolate over the warm water (cold climates) or take it off (hot climates) while you beat the cream cheese.
In a stand mixer (or using beaters, if you're brave) beat together the ROOM TEMP cream cheese and the sugar, until it is completely combined. This should take around 5 minutes. Slowly pour the chocolate and peanut butter mixture into the cream cheese (it shouldn't be too hot by now) stopping to scrape down the sides when necessary. Once the mixture is smooth and incorporated, add the eggs, one at a time, and continue to beat until the mixture is runny and completely smooth.
Pour the cheesecake mixture onto the chocolate base, and jiggle the pan to distribute evenly. Place into the oven for 30-40 minutes. Don't worry about cracks on the top, because it will be completely covered in chocolate anyway.
Once the cheesecake is done, remove it from the oven, and run a knife gently around the edge. This will discourage any more splits in the top. Allow to cool completely before topping with whatever you fancy - Whittakers and excessive chocolate drizzle totally optional.