Toast the Old-Fashioned Oats in a heavy pan over medium heat for 5–7 minutes until lightly golden.

In a separate saucepan, combine granulated sugar, brown sugar, water, and golden syrup. Heat over low until dissolved for 3–5 minutes.

Add the butter and increase heat to medium-high until the mixture reaches 310°F (154°C) on a candy thermometer.

Remove from heat, sprinkle baking soda, then add toasted oats and stir until coated.

Spread the mixture onto a buttered cookie sheet and let cool for 30 minutes until hardened.

Break into pieces and store in an airtight container.