Preheat oven to 375°. Grease and flour a 9 x 13 cake pan.
Whisk together all dry ingredients.
Cream butter with sugar. Add peanut butter, egg and water. Add dry ingredients. Press into cake pan and bake 15-20 minutes until brown around the edges. Cool 15 minutes.
In the meantime, melt caramels with cream. Stir and add vanilla. Spread hot caramel over crust and top with chocolate chips and chopped peanuts. After chocolate melts, I chill in refrigerator until chocolate is firm before attempting to cut.