Melt butter in large saucepan over low heat. Add cocoa and remove from heat. Stir in sugar and one egg at a time, mixing well after each. Add vanilla; then flour, salt and 1 cup of the pretzels.
Pour into greased 9×13 pan.
Sprinkle with remaining crushed pretzels and 1 cup chocolate chips. Press slightly into brownie batter.
Bake 20-22 minutes or until toothpick inserted in center comes out clean. Do not overbake!
Place caramel bits and milk in pyrex measuring cup and microwave for 30 seconds. Stir. Microwave another 30 seconds. Stir until completely melted and smooth.
Drizzle caramel over brownies.
If desired, sprinkle with coarse salt while caramel is still sticky.