Line a baking tray with grease proof paper/Silpat/a silicone mat and leave to one side.
Place white chocolate, some food colouring, vanilla and salt into a medium heat proof bowl and place in the microwave in 20 second increments, stirring in between each, until the chocolate is all melted and smooth.
Make sure you stir for a good 20 seconds before putting the chocolate back into the microwave as sometimes the chocolate is more melted than it looks!
At this stage, if you need more food colouring, add it in along with the vegetable oil.
Pour the melted chocolate onto your lined baking tray and use a small angled spatula to smooth and spread out the chocolate until level. You want it about 1/4 inch thick. My bark almost filled the entire baking tray, just with a little border around the edge.
Sprinkle, white chocolate and milk chocolate chips evenly all over the smoothed chocolate layer.
Finish off by sprinkling the crushed Oreo's all over the melted chocolate and lightly press with the palm of your hand to make sure it sticks to the melted chocolate.
Leave to cool for 30 minutes, then loosely cover with cling film and place in the fridge until set, around 2 hours.
Once set, break into as many pieces as you want and devour!
Red Velvet Oreo Bark will keep in an airtight container, at room temperature, for 4 days.