Does anyone know of a recipe that uses oil instead of butter and cocoa powder instead of chocolate chips  and has a shiny crispy top and chewy fudgy interior when baked (like a box mix)

Have you tried a dairy-free recipe? The oil is usually substituted for the butter. I think the fudgy part comes from the chocolate chips? The recipes I use are in Mimi Fix's book (Home Baking for Profit), and she uses oil and both cocoa powder and chocolate chips. It's 3/4 cup of flour with 1/4 cup of cocoa powder, and 1/2 cup of oil, if that helps. There is also an Almond Flour brownie that doesn't use chips, it's 1 cup of almond meal with 6 tablespoons of cocoa, with 1/2 cup of butter.