Line an 8x8" square baking dish with parchment paper or foil and lightly grease if it's foil, set aside.
Melt the chocolate chips and peanut butter in a microwave or on a stovetop using the double boiler method and set aside.
1 cup semi-sweet chocolate chips, 1/2 cup peanut butter
Melt butter and brown sugar in a large saucepan together over medium heat.
1 cup butter, 1/2 cup light brown sugar
Turn the heat down to low. Stir in vanilla. Add in oats. Cook for 2-3 minutes, stirring constantly
2 tsp vanilla, 3 cups quick oats
Press half of the oatmeal mixture into the prepared dish and press down firmly.
Add 3/4's of the chocolate peanut butter mixture and gently spread it on top. Make sure not to disrupt the base.
Gently sprinkle the remaining oat mixture on top and press it into place. Make sure the entire top is covered with the oat mixture.
Drizzle the remaining chocolate peanut butter mixture on top.
Set in the fridge to cool for 2-3 hours, or overnight, until the chocolate has completely set. Slice & enjoy!