Make the base
- Arrange a rack in the middle of the oven and heat the oven to 350°F.
Coat a 9x13-inch baking pan with cooking spray or butter and line the bottom of the baking pan with parchment paper.
- Melt 1 cup butter in a large saucepan. Add 1 cup creamy peanut butter, 1 cup packed light brown sugar, and 1/2 cup of honey.
Cook over medium heat until everything is melted and the mixture is smooth, about 3 1/2 minutes.
- Remove from the heat, add 1 tablespoon vanilla extract and 1 teaspoon salt, and stir to combine.
Add 4 1/2 cups instant rolled oats and stir until evenly coated.
Transfer to the prepared baking pan and press into an even layer.
Smooth the top (an offset spatula works best)
- Bake until lightly browned and you can see small bubbles popping all over it. (about 20 minutes)
Let the pan cool.
Make the topping:
- Place 1 cup milk chocolate chips, 1/3 cup creamy peanut butter, 1/4 cup heavy cream, and 2 tablespoons honey in a medium microwave-safe bowl
and microwave on high in 30-second bursts, stirring after each burst, until the mixture is smooth.
- Slowly and carefully pour the topping over the base. Using a spoon, spread it into a smooth and even layer. Refrigerate until the topping it set, about 2-3 hours.
- When ready to serve, run a paring knife around the edges of the pan to loosen the slab. Remove the slab from the pan and peel off the parchment paper if needed.
Cut the slab into rectangles (about 2 x 3 cm).