Line a large baking sheet (half-sheet size) with parchment paper to prevent sticking. Ensure it is laid flat and covers the entire surface.

In a large saucepan over medium heat, combine the butter, granulated sugar, and salt. Stir occasionally until the butter has fully melted. Bring the mixture to a boil and cook, stirring intermittently, until the toffee reaches a temperature of 285°F (137°C) as measured by a candy thermometer. The mixture should develop a rich golden-brown color.

Once the toffee has reached the correct temperature, promptly pour it onto the prepared baking sheet. Spread it evenly using a heatproof spatula. Allow it to set for 20 minutes in the refrigerator or until firm.

Following the package instructions, melt the Ghirardelli White Melting Wafers in a microwave-safe bowl, stirring at regular intervals until smooth.

Pour the melted white chocolate over the set toffee and spread evenly with an offset spatula.

Combine the granulated sugar and ground cinnamon in a small bowl. Sprinkle the mixture generously over the white chocolate layer while it is still wet. Allow it to set in the refrigerator for an additional 40 minutes.

If square pieces are desired, score the toffee with a plastic knife approximately 2–3 minutes after pouring, while the mixture is still soft. Repeatedly go over the scoring lines as it sets. Once the toffee has fully cooled and hardened, either separate the squares or break into rustic pieces.

Once set, the Churro Toffee is ready to be served. Store any leftovers in an airtight container.