Preheat oven to 325 degrees. To make the crust, in a small bowl, combine graham cracker crumbs, 2 T. sugar, and 1/4 c. melted butter. Once combined, press onto the bottom of a 9-inch spring-form pan. Bake for 10 minutes and then remove from oven. Readjust oven temperature to 450 degrees. Combine softened cream cheese, 3/4 c. granulated sugar, flour, and vanilla, mixing at medium speed with electric mixer until well blended. Add eggs, one at a time, mixing well after each addition. Reserve 1 c. cream cheese batter; stir in 1/2 c. caramel ice cream topping. Spoon half of plain batter over crust and cover with caramel batter. Sprinkle chopped pecans over caramel layer and spread remaining plain batter over pecans. Bake for 7 minutes, then reduce oven temperature to 250 degrees and continue baking for 30 minutes. Once the cheesecake is set, remove from oven and loosen the cake from rim of pan. Cool before removing rim of pan, then chill. To make the cheesecake topping, in a small saucepan, melt the brown sugar and 1 1/2 tsp. butter. Add water and bring to a boil. Add the pecan halves and cook for 2 minutes while stirring constantly. Spread on waxed paper and let cool. Before serving, brush the top of cheesecake with the 2 T. caramel ice cream topping and garnish with the candied nuts.