Preheat oven to 350 degrees F (175 degrees C) and grease an 8x8 inch baking pan.
In a large bowl, whisk together melted butter, granulated sugar, and brown sugar until combined.
Stir in the cookie butter, egg, and vanilla extract until smooth.
Fold in the flour, baking soda, and salt until just combined.
Stir in 3/4 cup of the chocolate chips.
Press the dough evenly into the prepared baking pan.
Sprinkle the remaining 1/4 cup of chocolate chips over the top.
Bake for 25 to 30 minutes, or until the edges are golden and a toothpick comes out mostly clean.
Allow to cool completely in the pan before cutting into squares.