Add all of the crust ingredients to a food processor and pulse until large crumbs form.
Pour in a tablespoon of ice water at a time until the dough sticks together when you squeeze it between your fingers, about ¼ cup of water in total.
Gently and quickly knead the dough into a large ball.
Roll out the dough into a large sheet.
Place the sheet into a 9 inch springform pan. Cover the bottom and sides and trim the edges so they do not hang over.
Cover and refrigerate for at least 1 hour or overnight.
Add all of the filling contents to a blender and blend until smooth. Set in the refrigerator for 20 minutes.
Preheat the oven to 400 F.
Pour the filling into the chilled crust and place in the preheated oven.
Lower the temperature of the oven to 325 F immediately. Bake for 2 hours or until filling has set and jiggles just slightly.
For the caramel topping, place ½ cup of the brown sugar and ¼ cup of the butter into a pot and cook on medium-low heat for 5 minutes, stirring with a wooden spoon frequently.
Add in the heavy cream, watch carefully for steam. Cook until thickened, about 2 minutes.
Turn off the heat and add in the vanilla extract. Stir and set aside.
Melt the butter with the flour in the microwave for 30 second increments or until the butter is melted.
Mix in the remaining brown sugar and stir until clumps form.
Top the warm pie with the streusel topping.
Allow the pie to cool to room temperature. Release the pie from the springform pan and drizzle with the caramel sauce.