Make the base focaccia dough - you can use my ‘Overnight Focaccia’ or ‘Same-Day Focaccia’ recipe.
Instead of using a 9x13 inch tray, opt to use a larger tray - 13x18 inches (or similar) is great.
When the focaccia dough has finished proofing, line the tray with nonstick parchment paper and coat it with a bit of olive oil.
Tip the dough onto the prepared tray and gently stretch it out into a rectangle shape.
Dot just under half of the cookie dough across the dough and then fold it up into thirds.
Preheat the oven to 210C/410F and place the baking rack into the lowest position in the oven.
Remove the inverted tray that's covering the focaccia dough, drizzle melted butter over the top, and dot the remaining cookie dough evenly over it.
Bake the focaccia for 19-23 minutes or until the bread is starting to brown up and the cookie dough has gone crisp on top.
Cool for at least 15-20 minutes before cutting in!