Melt chocolate: Start by melting the chocolate chips in a microwave-safe bowl at 50% power. Stir every 30 seconds until smooth.

Shape the cups: Spoon the melted chocolate into muffin liners, spreading it about 3/4 of the way up the sides. Allow to harden.

Whisk egg yolks: In a bowl, whisk together the egg yolks and granulated sugar until combined.

Heat cream: In a saucepan, heat 1 cup of heavy cream with vanilla and salt until hot, but do not boil.

Temper the eggs: Gradually add the hot cream mixture to the whisked egg yolks, stirring continuously.

Cook until thick: Cook the mixture over medium heat until thickened and reaches 170°F. Stir in the melted chocolate.

Whip remaining cream: Beat the remaining heavy cream until stiff peaks form, then fold it into the cooled chocolate mixture.

Make the caramel: Combine white sugar and corn syrup in a saucepan and cook until caramel color.

Finish caramel: Remove from heat and stir in salted butter, heavy cream, salt, and vanilla. Cool before using.

Assemble the cups: Spoon a layer of caramel into the hardened chocolate cups, then layer in the mousse. Drizzle remaining caramel and garnish.