Preheat the oven to 325°F. Grease a 9-inch springform pan well. Set it on two doubled-up sheets of heavy-duty foil (about an 18-inch square). Securely wrap the foil around the pan.

In a small bowl, combine the flour, brown sugar and pecans. Cut in the butter until crumbly, then press the mixture onto the bottom of the prepared pan. Place the pan on a baking sheet. Bake until set, 12 to 15 minutes. Let it cool on a wire rack.

In a large bowl, beat the cream cheese and sugars until smooth. Beat in the ¼ cup flour, then the cream and vanilla. Add the eggs and beat on low speed just until blended. Transfer 1 cup of the batter to a small bowl, and stir in the melted chocolate. Spread this chocolate-enhanced batter over the cooled crust.

In another bowl, mix the caramel topping with the remaining 1 teaspoon flour. Stir in the pecans. Drop spoonfuls of this mix over the chocolate batter. And then top with the remaining batter.

Place the springform pan in a large baking pan. To make a water bath, add an inch of hot water to the larger pan. Bake the cheesecake until the top appears dull in color, about one hour and 15 minutes to one hour and 30 minutes. Remove the springform pan from the water bath and carefully remove the foil.

Cool the cheesecake on a wire rack for 10 minutes. With a knife tip, loosen the sides from the pan, but do not remove the springform pan. Cool for another hour longer, and then refrigerate overnight.

Place the chocolate chips in a small heatproof bowl. In a small saucepan, bring cream just to a boil. Immediately and carefully pour over the chips. Whisk until the chocolate is melted and the mixture smooth. Allow to cool slightly, stirring occasionally.

Take the cheesecake out of the fridge. Remove the side of the springform pan. Spread the ganache over the cheesecake and sprinkle with pecans. Refrigerate again until set. Before serving, drizzle with additional caramel topping, if desired.