Graham Cracker Crust
Preheat oven to 350°F. Grease a 9-inch springform pan with nonstick baking spray.
Pulse graham crackers in food processor to crumbs. Add butter, sugar, salt and cinnamon. Pulse until combined.
Pour graham cracker mixture into greased pan. Use the underside of a measuring cup to pack crust into an even layer on the bottom of pan and 1 inch up the sides.
Bake for 10 minutes. Take out and cool completely.
Reduce oven to 325°F. Place the top rack in the center of the oven.
Using an electric mixer, beat cream cheese until smooth, about 1 to 2 minutes.
Add sugar, flour, salt and vanilla. Beat until smooth and light, about 2 to 3 minutes. It’s key to stop and scrape the bowl at least 2 times. There should be no lumps when complete.
Add eggs one at a time, mixing after each addition. Mix in heavy cream. Scrape down bowl.
Pour filling into springform pan with cooled graham crust. Prepare water bath (see notes).
Set springform pan inside large roasting pan and place in oven. Fill roasting pan with hot water, 1 to 2 inches up the sides of the springform pan.
Bake for 1 hour 45 minutes to 2 hours. Key: Do not over bake. Edges will be set, and the center will still be slightly wobbly. The top should have a light golden color (you can cover with foil if cheesecake browns too quickly). An instant thermometer will read 155°F when placed in the center.
Turn off oven and crack open the door, letting cheesecake cool in oven for an hour.
Take out of oven and transfer to cooling rack, letting cool for another hour. Then transfer to fridge to chill for 4 to 8 hours, or overnight.
Spread sugar evenly on the bottom of a medium saucepan over medium heat. Allow sugar to melt and caramelize, swirling as needed to promote even caramelization. Do not stir. This step will take about 10 minutes.
When caramel turns dark amber in color, reduce heat to low. Gradually add heavy cream while constantly whisking. Caramel will aggressively bubble.
Stir caramel sauce over low to medium heat until all clumps have dissolved, and mixture is smooth. Remove from heat and stir in butter, then vanilla and salt. Cool to room temperature.
Pour ½ cup of caramel sauce over chilled cheesecake, generously covering the top. Let set for a few minutes, then sprinkle on flaky salt.