1Preheat your oven to 350°F (175°C) and grease a 9x13 inch baking pan.
In a large mixing bowl, cream together the butter and sugar until light and fluffy.
Add the oil and mix until well combined.
In a separate bowl, whisk together the hot chocolate mix, flour, corn starch, baking soda, and salt.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Add the water and mix until the dough comes together.
Press the dough evenly into the prepared baking pan.
Bake for 18-20 minutes, or until the edges are lightly golden.
Allow the bars to cool completely in the pan before cutting into squares.
Serve and enjoy your Hot Chocolate Sugar Cookie Bars!