For the cookies:
1/2 cup unsalted butter, room temperature
1/2 cup granulated sugar
1/4 cup light brown sugar
1 egg, separated
2 tablespoons half and half or light cream
1 teaspoon vanilla bean paste or vanilla extract
1/3 cup cocoa powder
1/2 teaspoon salt
1 cup all-purpose flour
1 1/4 cups finely chopped pecans
Sea salt for garnish
For the caramel filling:
3/4 cup sugar
1/4 cup water
1/2 cup heavy cream
1 tablespoon unsalted butter
For the cookies:
- Preheat oven to 350°F. Line a 11x17-inch cookie sheet with parchment paper and set aside.
- In the bowl of an electric mixer, cream butter and both sugars on medium speed until light and fluffy, about 5 minutes.
- Add egg yolk, half and half and vanilla, scraping down the bowl as needed.
- Add cocoa powder, salt and flour, mixing until combined.
- Wrap cookie dough in plastic wrap and refrigerate for about 90 minutes, or until firm enough to work with.
- In a small bowl, whisk egg white until foamy and set aside. Place chopped pecans in a separate bowl.
- Shape dough into 1-inch balls. I recommend using a cookie scoop that yields 3/4 ounce portions. Dip into egg white, roll in pecans and place on prepared cookie sheets. Using the handle of a wooden spoon, make an indentation in the middle of each cookie. Refrigerate cookies for 10 minutes until firm.
- Bake cookies for 12-14 minutes, until the centers are set. Transfer to a cooling rack and if needed, go over the indentations with the wooden spoon handle to make sure you have enough room for the caramel.
For the caramel sauce:
- In a medium saucepan, combine sugar and water and mix by hand (it ill feel like wet sand). Set saucepan over medium heat and cook until sugar dissolves. Increase the heat to high and cook without stirring, occasionally brushing down the sides of the pan with a wet pastry brush. Cook until the sugar turns a golden, amber color, about 4-7 minutes. Keep a close eye on it as once it starts to get color, it goes very quickly.
- Remove the saucepan from the heat and carefully stir in the heavy cream. Please be aware the mixture will bubble up when cream is added so be cautious. Whisk in butter until smooth.
- Transfer caramel sauce to a jar and refrigerate for at least one hour before filling the cookies.
To fill the cookies:
- Spoon chilled caramel into the cookies using a 1/2 teaspoon, or use a piping bag. Garnish with sea salt if desired. Store filled cookies in an airtight container.