Place the Chocolate crumbs in a bowl, add the sugar, and stir. Melt butter in the microwave, and pour over the chocolate crumbs. Stir well to combine. Line the bottom of a 6-inch Spring-form pan with Parchment paper. Lightly grease the sides of the Spring-form pan with Butter. Place the crumbs in the pan, on the parchment. Press evenly into the pan, and set aside.
In the mixing bowl of a stand mixer, add the Cream Cheese. Sugar, and Yogurt, and Vanilla, and mix until well blended, creamy, and smooth. Add the eggs, and mix. Crush the Whoppers, and fold into the cheesecake filling with a spatula. Pour the cheesecake filling into the Spring-form pan, on top of the chocolate crumbs.
Place the frosting in the refrigerator to chill, for easier piping to decorate.
Pour the 1/2 cup of water into the bottom of the Instant Pot. Place the Trivet in the bottom of the Instant Pot. Cover the Spring-form pan with Foil, and place the Spring-form pan in the lifter that came with the Instant Pot. Lift the pan into the Instant Pot, and set it on the Trivet, leaving the lifter in the Instant Pot, so you can easily lift out the cheesecake when done. Place the lid on the Instant Pot, and make sure the Pressure Valve is set to 'SEALING'. Press the 'PRESSURE COOK' button, and set the time for 55 minutes. When the Instant Pot is finished cooking, allow the pressure to be released Naturally. When the Float Valve has dropped down, make sure all the pressure has been released by gently turning the pressure valve to 'VENTING'. Remove the lid, and carefully lift out the cheesecake, and set it on a wire rack to cool. Cheesecake may still be a little wobbly in the center but will set up in the refrigerator. Allow the cheesecake to cool completely. Then, wrap in Parchment paper, and foil, and refrigerate overnight. I like to make this ahead of time and keep in the refrigerator for 24 hours, before serving.