Line a rimmed sheet pan with parchment and lightly oil the parchment and a spatula.
Toast sesame seeds in a dry skillet over medium heat until lightly golden and fragrant, 3–5 minutes. Set aside.
Combine sugar, corn syrup, water, and salt in a medium heavy saucepan. Cook over medium heat, stirring just to dissolve.
Increase heat to medium-high and boil without stirring until the syrup reaches 300°F (hard-crack), 8–10 minutes. Swirl the pan if needed.
Remove from heat. Quickly stir in butter and vanilla until smooth.
Sprinkle in baking soda and stir; the mixture will foam and lighten.
Fold in toasted sesame seeds, then immediately pour onto the prepared pan and spread thin with the oiled spatula.
Cool completely until hard, about 20 minutes. Break into shards and store airtight.
Notes
Try half white and half black sesame seeds for contrast, or finish with a pinch of flaky sea salt. For a flavor twist, stir in a dash of toasted sesame oil or a pinch of cayenne with the vanilla. Store brittle in an airtight container at room temperature, layered with parchment, for up to 2 weeks.This recipe is an original creation inspired by classic Easy Sesame Brittle Recipe flavors. All ingredient ratios and instructions are independently developed.