Gather ingredients: sugar, butter, milk or cream, chocolate or flavoring, vanilla, and salt
Line an 8×8-inch pan with parchment paper or lightly grease it
Combine sugar, butter, and milk or cream in a saucepan
Heat over medium heat, stirring until the sugar dissolves
Bring the mixture to a boil
Cook to the soft-ball stage, about 234–240°F
Remove from heat
Add chocolate, vanilla, and salt
Stir until smooth and fully combined
Beat the mixture until it thickens and loses some gloss
Pour into the prepared pan
Spread evenly
Let it cool at room temperature until set
Cut into squares
Store in an airtight container