Add sugar and cornstarch to large mixing bowl and whisk together. Then add cream cheese and blend until smooth.
Mix in eggs one at a time until fully incorporated. Then add Bailey’s and vanilla and beat until just combined.
Remove cheesecake crust from freezer and pour batter into pan. Cover pan with foil.
Add 1 1/2 cups water and 3-inch trivet to Instant Pot. Place pan on top of 2-inch trivet and cook for 40 minutes at high pressure.
Once cook time is complete, allow pressure to release naturally. Then carefully remove cheesecake from pot. Remove foil and allow cheesecake to cool for one hour or until room temperature.
Once cool, carefully run a paring knife around the edge of the cheesecake to separate from pan. Refrigerate for at least 6 hours, preferably overnight. Carefully push cheesecake up from push pan by placing center of push pan on a can or glass and pushing edges down. If using springform pan, gently remove outer edge of pan.