• Preheat the oven to 250°F. Line two rimmed half-sheet pans with parchment paper and set aside.

Make the Praline Sauce (Microwave Option)

• In a large microwave-safe mixing bowl, combine the butter, brown sugar, and corn syrup. Microwave on HIGH for 1½ minutes, then carefully stir. (The bowl will be hot!)
• Return to the microwave and heat for another 1–2 minutes, until the mixture comes to a full boil. (Time will depend on your microwave's wattage.)
• Remove from the microwave and immediately stir in the baking soda, vanilla, and cinnamon. The mixture will foam slightly, thicken, and turn lighter and opaque.

Make the Praline Sauce (Stovetop Option)

• In a heavy-bottomed pot with high sides, melt the butter over medium heat. Stir in the brown sugar and corn syrup, and bring to a full rolling boil. Let it boil for 30 seconds, then remove from the heat.
• Stir in the baking soda, vanilla, and cinnamon. Like the microwaved sauce, the stovetop sauce will foam up and take on a lighter, creamy look.

Coat the Cereal

• In a large mixing bowl (or two medium bowls), combine half of the Corn Chex, half of the Cinnamon Toast Crunch (about 5 cups Chex and 4 cups Cinnamon Toast Crunch), and 2 cups chopped pecans.
• Gradually pour half of the warm praline sauce over the cereal mixture. Use a rubber spatula to fold the sauce in until evenly coated.
• Spread the coated cereal in an even layer on one of the prepared baking sheets.
• Repeat the process with the remaining cereal, pecans, and sauce, using the second baking sheet.

Bake and Cool

• Bake for 1 hour, stirring every 20 minutes to help the cereal and coating toast evenly. Remove from the oven and cool completely on the pans. The coating will seem soft at first but will turn crisp and crunchy as it cools.
• Once cooled, break the mixture into bite-sized chunks. Store in an airtight container at room temperature. It'll stay crispy for about 1 week.