01 -
Gather all caramel ingredients. Ensure the heavy cream is at room temperature or slightly warm to prevent the caramel from seizing.
02 -
In a heavy-bottomed saucepan, combine sugar and water. Stir gently to mix, avoiding sugar sloshing against the pot sides. Heat over medium until sugar dissolves.
03 -
Allow the mixture to bubble and change color from clear to amber. Stir gently if browning unevenly. Remove from heat once evenly amber.
04 -
Whisk in butter, then gradually add heavy cream while whisking gently. Mix until smooth.
05 -
Whisk in vanilla and salt. Return the mixture to medium heat and cook for 2 minutes. Remove from heat and whisk in flour. Set aside to cool.
06 -
Preheat oven to 175°C (350°F). Grease and line an 8×8-inch baking dish with parchment paper.
07 -
In a medium bowl, whisk together oats, flour, baking powder, and salt. Set aside.
08 -
In a large mixing bowl, cream butter and dark brown sugar until smooth. Mix in the egg, egg yolk, and vanilla. Combine with the dry ingredients. Mix in the semisweet chocolate chips just before the dough is fully combined.
09 -
Spread 2/3 of the dough evenly in the prepared baking dish. Sprinkle with an even layer of chopped nuts. Bake for 8 minutes and refrigerate remaining dough.
10 -
Remove the base from the oven. Top with dark chocolate chips, then pour over the caramel. Heat the caramel slightly if it's too thick. Spread caramel evenly over the chocolate.
11 -
Top the caramel layer with blobs of the remaining dough. Bake for 20-25 minutes or until lightly golden.
12 -
Cool at room temperature for 30 minutes, then chill for 1 hour. Remove from pan, sprinkle with flaky sea salt, slice, and serve.