Heat the oven to 350°F. Pulse the pecans, oats, brown sugar, flour, cinnamon, and salt in a food processor until you have coarse crumbs. Then add the melted butter and pulse again until the mixture starts to clump together. Press the crumbs firmly into the bottom and about 1 inch up the sides of a 9-inch springform pan.

Bake the crust for 12 minutes, then set it on a rack to cool.

Place all the filling ingredients in a blender and blend until completely smooth. Stop as needed to scrape down the sides so everything mixes evenly.

Boil 2 quarts of water. Wrap the outside of the springform pan in foil to help prevent leaks, then place it in a large baking dish. Pour the filling into the crust, and then pour the boiling water into the outer dish until it comes about 1 inch up the side of the pan.

Bake for 50 to 60 minutes, or until the edges are firm and the center is just set.

Refrigerate the cheesecake for about 4 hours, or until it is fully chilled. Then run a thin knife around the edge and remove the pan sides. Just before serving, whip the heavy cream, brown sugar, and vanilla to soft peaks. Spread the whipped cream over the top and dust with cinnamon.