Step 1

Begin to melt the butter and peanut butter in a medium to large saucepan set over low heat.

Step 2

Add in the marshmallows and stir occasionally until about 75% melted.

Step 3

Remove from heat and continue to stir, pressing down on the marshmallows, until completely melted.

Step 4

Alternatively, you can melt the butter, peanut butter, and marshmallows in the microwave using bursts of high power for 1 to 1 1/2 minutes.

Step 5

Pour the melted marshmallows over the cereal and stir until well coated.

Step 6

Gently press the cereal mixture into a buttered 8-inch or 9-inch pan.

Step 7

Let cool for at least 30 minutes before cutting into 16 squares.