Prepare your baking sheet by lining it with parchment paper.

Combine dry ingredients: oats, crispy rice cereal, and pecans in a large heatproof bowl.

Heat butter, granulated sugar, light brown sugar, and milk in a saucepan until boiling, about 3-5 minutes. Boil for 1 minute.

Remove from heat and stir in vanilla extract.

Pour the hot mixture over the dry ingredients and mix quickly until combined.

Scoop mixture onto the prepared baking sheet to form rounded bites.

Chill in the refrigerator for at least 30 minutes or until firm.

Whisk together powdered sugar, milk, and vanilla extract until smooth for the glaze.

Drizzle the glaze over the firm bites.

Let the bites sit at room temperature until the glaze hardens slightly.