"The inspiration for these sinfully rich-tasting cookies combines my obsession with shortbread, dulce de leche, and a restaurant cream cheese dessert." –Jennifer Brumfield, Bellingham, Wash.
1. Preheat oven to 325°.
2. To prepare cookies, weigh or lightly spoon flour into dry measuring cups; level with a knife. Combine flour, cocoa, and next 4 ingredients (through ancho chile powder) in a bowl; stir with a whisk.
3. Place 1/2 cup butter in a large bowl; beat with a mixer at medium speed until light and fluffy. Gradually add oil; beat 3 minutes or until well blended. Gradually add 3/4 cup powdered sugar; beat well. Add flour mixture; beat at low speed until well blended. Cover and chill 30 minutes.
4. Shape dough into 36 balls. Place 2 inches apart on an ungreased baking sheet. Flatten cookies to 1/4 inch thickness. Bake at 325° for 20 minutes. Cool 1 minute on baking sheet. Remove from baking sheet to a wire rack; cool completely.
5. To prepare icing, melt 2 tablespoons butter in a large saucepan over medium heat. Add 1/2 cup brown sugar and milk; cook 1 minute or until sugar dissolves, stirring constantly. Bring to a boil; reduce heat, and simmer 3 minutes or until slightly thickened, stirring occasionally. Remove from heat; cool to room temperature. Add powdered sugar and vanilla, stirring with a whisk until smooth.
6. To prepare nuts, combine 1 teaspoon brown sugar, sea salt, and 1 teaspoon butter in a medium bowl. Arrange pecans on a baking sheet. Bake at 325° for 10 minutes or until toasted. Add hot pecans to butter mixture, tossing well to coat. Cool.
7. Spread 1 teaspoon icing over each cookie; top each with 1 pecan half.