Preheat oven to 350 degrees F.

Line an 8 by 8-inch square baking pan with parchment paper. Let parchment come up over the sides of the pan to use as "handles" when unmolding after baking. In a mixer bowl, combine flour, butter, and brown sugar. Blend at low speed until incorporated and mixture is like sand, about 2 to 3 minutes. Stir in nuts. Reserve 1 cup of mixture for topping. With your fingers, press remaining mixture into pan. Bake on the middle rack of the oven until crust is set and golden brown, about 8 to 10 minutes. Let cool on a rack while assembling the filling.

In a clean mixer bowl, combine cream cheese and sugar. Blend until smooth, then add the remaining filling ingredients, beating until smooth. Spread evenly over baked crust. Sprinkle the reserve crust mixture over filling. Bake until top is golden brown and filling is set, about 25 to 30 minutes. Let cool completely on a rack, then use parchment "handles" to remove from pan in 1 piece. Cut into bars, squares or festive shapes with cookie cutter of your choice. Sprinkle with red and/or green sanding sugar, if desired.