Line a 12-by-17-inch rimmed baking sheet with parchment paper.
Bring sugar, honey, and water to a boil in a medium saucepan without stirring. Reduce heat to medium-high. Cook, stirring occasionally, until a candy thermometer reaches 300 degrees.
Remove from heat, add baking soda, and stir with whisk just until incorporated.
Gently pour mixture onto baking sheet without spreading. Let cool. Break into pieces.
Recipe by Chateau Elma at https://www.chateauelma.com/honey-sponge-toffee