Prepare the cranberry filling first. - In a medium sized saucepan, place all the ingredients. Then, over medium-high heat, cook the ingredients until boiling. Continue to boil the filling until it becomes thick and syrup, about 5 minutes. Remove from heat and let cool while you make the shortbread.
In a food processor, mix flour, oats and sugar 10 seconds.
Add 1 cup butter; mix until mixture forms a ball.
Set aside ½ cup of mixture.
Mix in yolks.
Press yolk mixture into pay. Spread with cranberry filling. Sprinkle walnuts and chocolate chips, then press into dough. Form pea-sizes crumbs with reserved dough mixture, sprinkle over top.
Bake at 350F until topping is pale gold, about 45 minutes. Cool on rack and cut into 24 bars.