Turtle Cheesecake

1 cup all-purpose flour
1/3 cup packed brown sugar
1/4 cup finely chopped pecans
6 tablespoons cold butter, chopped

FILLING:
4 packages (8 ounces each) cream cheese, softened
1 cup sugar
1/3 cup packed brown sugar
1/4 cup plus 1 teaspoon all-purpose flour, divided
2 tablespoons heavy whipping cream
1-1/2 teaspoons vanilla extract
4 eggs, lightly beaten
1/2 cup milk chocolate chips, melted and cooled
1/4 cup caramel ice cream topping
1/3 cup chopped pecans

GANACHE:
1/2 cup milk chocolate chips
1/4 cup heavy whipping cream
2 tablespoons chopped pecans
Optional garnish: pecan halves and additional caramel ice cream topping"