A butterscotch treat (filipino buttery bar)

For the butterscotch sauce:
In a saucepan,put water and sugar.Cook the mixture in high heat.Don't stir.Let the water evaporate.Once the sugar has thickened and the color turned to light brown,add the butter and whisk the mixture until smooth.Then add the cream and vanilla and whisk again until smooth and thick.Pour into a jar and set aside in the fridge.
For the Butterscotch Bar:
In a bowl combine 1/2 cup flour,baking powder,2 tbsp sugar,yeast and Set Aside.
Heat milk and butter until very warm and gradually add to the flour mixture.
Beat the mixture for 2 minutes at medium speed.
Then add egg yolk,another ½ cup flour and beat for 2 minutes in a high speed this time.
Now the most exciting part stir in 3/4 cup butterscotch sauce,
Followed by the remaining 1 cup flour to make a stiff batter.
Cover tightly with plastic wrap.Set aside in the fridge for 2 hours.
Combine 1 cup chocolate chips,1/2 cup brown sugar and cinnamon.
Roll dough using choco chips cinnamon sugar mixture
Sprinkle with 1/2 cup of choco chips cinnamon sugar mixture
Fold ends over center (like folding a letter).
Repeat rolling, sprinkling, and folding procedure twice more using choco mixture
Finally place the dough in a square baking pan 8 x 8-inch square with wax paper
Spread 1/2 cup butterscotch sauce on top.
Let rest 10 minutes.Bake at 375°F for 30 minutes.
Remove from pan,cool.Cut into bars and prepare for a big surprise