1 cup all-purpose flour
1/3 cup cocoa powder
1/4 teaspoon salt
8 tablespoons (1 stick) unsalted butter, softened
2/3 cup sugar
1 large egg, separated, plus 1 egg white
2 tablespoons milk
1 teaspoon vanilla extract
1 1/4 cups pecans, chopped fine
14 soft caramel candies
3 tablespoons heavy cream
- Combine flour, cocoa, and salt in bowl. With electric mixer on medium-high speed, beat butter and sugar until light and fluffy, 2 minutes. Add egg yolk, milk, and vanilla and mix until incorporated. Reduce speed to low and add flour mixture until just combined. Wrap dough in plastic wrap and refrigerate until firm, 1 hour.
- Adjust oven rack to upper-middle and lower-middle positions and heat oven to 350 degrees F. Line 2 baking sheets with parchment paper. Whisk egg whites in bowl until frothy. Place pecans in another bowl. Roll dough into 1-inch balls, dip in egg whites, then roll in pecans. Place balls 2 inches apart on prepared baking sheets. Using 1/2-teaspoon measure, make indentation in center of each ball. Bake until set, about 12 minutes, switching and rotating sheets halfway through baking.
- Microwave caramels and cream in bowl, stirring occasionally, until smooth, 1 to 2 minutes. Once cookies are removed from oven, gently re-press existing indentations. Fill each with 1/2 teaspoon caramel mixture. Cool 10 minutes, then transfer to wire rack to cool completely.