Step 1

Combine unsweetened chocolate and butter in a small, heavy saucepan. Cook over low heat, stirring constantly until melted.

Step 2

Let stand 10 minutes.

Step 3

Beat eggs at medium speed of an electric mixer until thick and lemon-colored. Gradually add sugar, beating well.

Step 4

Add flour, salt, vanilla, and unsweetened chocolate mixture to the eggs at low speed for 1 minute.

Step 5

Spoon mixture into a lightly greased and floured 13 x 9 x 2 pan.

Step 6

Bake at 350 degrees (F) for 25-30 minutes or until a toothpick poked into the center comes out clean with no batter stuck to it.

Step 7

Cool 20 minutes; spread creme de menthe frosting over top. Chill for at least 4 hours.

Step 8

After the 4 hours are up and the brownies are completely cooled, melt 3/4 cups chocolate chips. Drizzle melted chocolate over frosting layer of brownies, or pipe-in desired design. The chocolate will harden on contact with the cooled frosting layer so you will want to cut bars immediately.

Step 9

Remove from pan and chill for at least 1 hour. Store in an airtight container in the refrigerator.

Step 10

Combine all ingredients except walnuts in a mixing bowl.

Step 11

Beat with an electric mixer on high until smooth.

Step 12

Stir in the walnuts, if wanted.