In a large mixing bowl, measure out the 200g of oats and set them aside.
In a medium-sized saucepan over low heat, melt the 100g of unsalted butter.
Stir in 200g of granulated sugar, 60ml of whole milk, and 30g of cocoa powder into the melted butter. Mix well and bring the mixture to a gentle boil. Allow it to boil for about 2 minutes, stirring constantly.
Remove the saucepan from heat and immediately add 100g of peanut butter and 1 tsp of vanilla extract. Stir until the peanut butter is completely melted, and the mixture is smooth.
Pour the chocolate peanut butter mixture over the oats in the mixing bowl. Stir until the oats are evenly coated.
Using a spoon, drop spoonfuls of the mixture onto parchment paper or a baking sheet to form cookies. Let them cool and set for about 30 minutes.
