• Preheat the oven to 350°F (176°C).
• Combine vanilla wafer crumbs and brown sugar in a medium bowl. Stir in the melted butter with a spatula. Press the mixture into the bottom and halfway up the sides of a 9-inch (23cm) springform pan. Bake for 6 minutes and let cool.
• Combine all the pecan filling ingredients in a medium saucepan. Stir well and bring to a boil over medium-high heat. Reduce the heat to maintain a simmer and cook, stirring continuously, until the mixture thickens, about 8 to 10 minutes. Pour into prepared crust.
• Reduce the oven temperature to 325°F (160°C).

To make the cheesecake

• Beat the cream cheese in a stand mixer at medium speed until smooth and creamy. Add the brown sugar and flour, and beat until fluffy. Add the eggs one at a time, beating well after each addition.
• Use a rubber spatula to scrape down the sides of the bowl to make sure everything mixes evenly. Add the cream and vanilla and beat until just combined. Pour the mixture over the pecan filling.
• Place the pan in the oven and bake for 1 hour. Turn the oven off the oven, but leave cheesecake in the oven with the door closed for 1 more hour.
• Remove the cheesecake from the oven and run a knife around the sides to make sure the cheesecake is not sticking. Let it cool completely on a countertop, and then refrigerate for at least 4 hours.
• Slice and serve with Dulce de leche, if desired.