Bourbon-Sea Salt Caramels

Lightly coat an 8x8" baking pan with nonstick spray and line with parchment paper, leaving a 2" overhang on 2 sides; spray parchment. Bring sugar, corn syrup, and 1/2 cup water to a boil in a medium saucepan over medium-high heat, stirring to dissolve sugar. Cook, swirling pan occasionally, until mixture turns a deep amber color, 8 –10 minutes. Remove pan from heat and whisk in sweetened condensed milk and butter (mixture will bubble vigorously) until smooth. Fit pan with thermometer and return to medium-low heat. Cook, whisking constantly, until thermometer registers 240 °F. Remove from heat and whisk in bourbon and kosher salt. Pour into prepared pan; let cool. Sprinkle caramel with sea salt, cut into 3/4" pieces, and wrap individually in parchment paper. DO AHEAD: Caramels can be made 2 weeks ahead. Store wrapped tightly in plastic in airtight container at room temperature.