Step 1

Line an 8-inch or 9-inch square baking dish with parchment paper and set aside. Overhangs the edges of the foil to lift the bars easier from the baking dish. (You can use a 9x13-inch if you want thinner bars.)

Step 2

Melt butter and brown sugar in large saucepan over medium heat, until the butter has melted and the sugar has dissolved. Stir in vanilla. Mix in the oats.

Step 3

Cook over low heat 3 to 4 minutes, or until ingredients are well blended.

Step 4

Pour half of the oat mixture into the prepared baking dish. Spread out the mixture evenly, pressing down. Reserve the other half for second layer.

Step 5

To make the filling, melt the peanut butter and chocolate chips together in a small microwave-safe bowl and stir until it’s smooth.

Step 6

Pour the chocolate mixture over the crust in the pan, reserving about 1/4 cup for drizzling and spread evenly.

Step 7

Pour the remaining oat mixture over the chocolate layer, pressing in gently and drizzle with the remaining chocolate mixture.

Step 8

Refrigerate 2 to 3 hours or overnight. Bring to room temperature before cutting into bars.

Step 9

Note: Like any no-bake cookie, the final texture of these really depends on how long you boil the sugar mixture. If it doesn't boil long enough, the cookie/bars mixture will be too soft, if you boil too long, they could turn out dry and crumbly.