Preheat oven to 340°F.
Line a 9x13-inch baking dish with parchment paper.
Beat butter and sugar until creamy.
Mix in egg yolk and salt.
Add flour and mix until a soft dough forms.
Press evenly into prepared pan.
Bake 20–25 minutes until lightly golden.
Cool completely.
Add butter, brown sugar, salt, sweetened condensed milk, and corn syrup to a saucepan.
Heat over medium-low heat until smooth.
Increase heat to medium and cook, stirring constantly, for about 6 minutes or until thickened and golden.
Pour over the cooled crust and spread evenly.
Microwave chocolate and cream in 30-second intervals, stirring until smooth.
Pour over caramel and spread evenly.
Refrigerate until the chocolate is set.
Slice and serve.
