Preheat oven to 350 degrees F/ 325 degrees F convection.  Oil an 8 inch square pan.

In a large bowl, beat oil and sugar until well combined and lightened in color and texture.  Beat in the egg, vanilla, and espresso.  Stir in the flour and salt, followed by the chips.

Spread into the prepared pan and bake about 20 minutes, until golden brown and a toothpick inserted in the center comes out clean or with a few moist crumbs.  Serve warm or cool completely in the pan.  Blondies may be stored in an airtight container at room temperature for up to 4 days, or frozen, wrapped in parchment and foil and placed in a zipper bag for up to 3 months.  Thaw in the microwave about 30 seconds.