• Preheat oven to 350℉. Coat bottoms of 2 (8-inch) cake pans with cooking spray (do not coat sides of pans); line bottoms with parchment paper. Coat parchment paper with cooking spray; dust with 1 tablespoon flour.
• In a medium saucepan, combine boiling water and cocoa powder, stirring well with a whisk. Cool completely.
• Place granulated sugar, 6 tablespoons butter, and vanilla extract in a large bowl; beat with an electric hand mixer at medium speed until well blended. Add eggs to butter mixture, 1 at a time, beating well after each addition.
• In another mixing bowl, combine flour, baking soda, baking powder, and salt, stirring well with a whisk. Add flour mixture and cocoa mixture alternately to sugar mixture, beginning and ending with flour mixture.
• Pour batter into prepared pans, sharply tap pans once on counter to remove air bubbles. Bake for 30 minutes or until a wooden pick inserted in center comes out clean Cool in pans 10 minutes on wire rack, and remove from pans. Cool completely on wire rack.

For the Frosting

• In a small saucepan over medium heat, melt 2 tablespoons butter. Add brown sugar and 2 tablespoons milk, and cook 1 minute or until sugar melts. Remove from heat; cool slightly.
• Combine buttter mixture and 2 teaspoons vanilla in a large bowl. Gradually add powdered sugar, beat with a mixer at medium speed until smooth. Add additional milk, 1 teaspoon at a time, beating until spreading consistency.

Assembling the Cake

• Place 1 cake layer on a plate, and spread top with half of frosting. Place caramel topping in a small zip-top plastic bag. Snip a small hole in 1 corner of bag and drizzle half of caramel over frosting.
• Top with other cake layer. Spread remaining frosting over top of cake, and drizzle with remaining caramel topping. Sprinkle with pecans.