Heat oven to 350°F. Line an 8-inch square pan with parchment, leaving overhang.
Toast coconut on a sheet pan until golden, 6–8 minutes, stirring once. Cool completely.
Beat softened butter and sugar until creamy. Mix in 1 tsp vanilla and 1/4 tsp salt.
Add flour and mix just until a soft dough forms. Press evenly into the lined pan.
Bake crust until edges are lightly golden, 18–22 minutes. Set the pan on a rack.
Melt caramels, cream, and 1.5 tbsp butter over low heat, stirring until smooth and glossy.
Stir in remaining 1 tsp vanilla and 1/4 tsp salt. Fold in the toasted coconut.
Spread coconut-caramel over the warm crust. Press gently to level. Chill 15–20 minutes.
Microwave chocolate chips with oil in 20-second bursts, stirring, until smooth and pourable.
Spread a thin chocolate layer on top. Drizzle extra over lines. Sprinkle flaky salt, if using.
Chill until set. Lift out by parchment and slice into 16 bars with a warm knife.