Mix the sugar, butter, eggs and cocoa until just blended. Slowly add flour and one teaspoon of the vanilla. Mix until just blended. Spread batter in pan and top with chopped pecans.
Bake about 25 minutes. Let cool on wire rack.
In saucepan over low heat, melt caramels, stirring until smooth. Remove from heat and stir in remaining vanilla. Drizzle over brownies in parallel rows and press pecan halves into the caramel in neat rows. Let set for at least 10 minutes