Line a 18cm x 27cm baking tray with baking paper.
Place butter, brown sugar and vanilla flavour in a medium saucepan, cook over low heat until brown sugar well dissolved.
Add in Dr. Oetker Quick Cook Oats and salt, stir for 4 to 5 minutes.
Transfer 1/3 oat mixture into the baking tray. Spread out the mixture evenly, pressing down.
Melt Dr. Oetker Nona Cooking Chocolate over a saucepan. Add in peanut butter and stir until well combined.
Pour 4/5 of the chocolate sauce on top of the oats layer.
Top with the remaining oat mixture, drizzle with chocolate sauce and sprinkle with chocolate chips.
Keep in the refrigerator for 4 hours (until set) before cutting.