For the shortbread layer:
1 1/2 cups all-purpose flour
3/4 cup firmly packed light brown sugar
1/2 cup butter, softened
1/2 cup finely chopped pecans
For the cheesecake layer:
2 (8-ounce) packages cream cheese, softened
1/2 cup sugar
1/2 cup milk
2 teaspoons vanilla extract
For the pecan pie layer:
3/4 cup firmly packed light brown sugar
1/2 cup light corn syrup
1/3 cup butter, melted
3 large eggs
1/2 teaspoon vanilla extract
1/4 teaspoon salt
1 1/2 cups finely chopped pecans
Preheat oven to 350.
For the shortbread layer: In a medium bowl, combine flour and brown sugar. Using a pastry blender, cut in butter until mixture resembles coarse crumbs. Stir in 1/2 cup pecan. Press mixture evenly into bottom of a greased 9x13" baking pan. Bake for 10 minutes; remove from oven, and cool for 10 minutes.
For the cheesecake layer: Place the cream cheese and sugar in the bowl of a stand mixer and beat at medium speed until smooth. Add milk and vanilla and beat until combined. Pour the cream cheese mixture over the cooled shortbread layer. Bake for 15 minutes; remove from oven and cool for 10 minutes.
For the pecan pie layer: In a medium bowl, combine brown sugar, corn syrup, and melted butter. Gently stir in the eggs, salt, and vanilla extract. Stir in pecans. Pour pecan mixture over cooled cheesecake layer. Bake for 30-35 minutes, or until center is set and pecan pie layer is a rich brown color.