Line a baking sheet with parchment paper, ensuring it's flat and ready for the treats.

In a large heatproof bowl, mix together old-fashioned rolled oats, crispy rice cereal, and chopped pecans until evenly combined.

In a medium saucepan over medium heat, combine butter, granulated sugar, light brown sugar, and milk, stirring until it gently boils for 1 minute.

Remove from heat and stir in vanilla extract.

Pour hot sugar mixture over dry ingredients and quickly fold together until well incorporated.

Scoop rounded spoonfuls of the mixture onto the lined baking sheet, leaving space between each scoop.

Refrigerate for at least 30 minutes until firm.

In a medium bowl, whisk together powdered sugar, milk, and vanilla extract until smooth.

Drizzle glaze over the chilled bites, coating them generously.

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