Preheat oven to 325°F. Line a 13x9x2-inch baking pan with foil, extending the foil over edges of pan. Grease foil; set pan aside. In a medium heavy saucepan heat and stir the chocolate and the 3 tablespoons butter over low heat until chocolate melts. Remove from heat. Cool; set aside.
For filling, in a medium bowl combine goat cheese and the 2 tablespoons butter. Beat with an electric mixer on medium speed for 30 seconds. Add the 1/4 cup sugar; beat until fluffy. Add the 1/4 cup flour, honey, and one of the eggs; beat well. Set aside. Wash and dry beaters thoroughly.
For batter, in a large bowl beat the two remaining eggs with an electric mixer on medium speed until foamy. Add the 1 1/4 cups sugar, the water, and vanilla; beat well. Beat in the cooled chocolate mixture. Stir in the 1 cup flour, baking powder, salt until well combined. Stir in nuts. Spread half of the batter in the prepared pan.
Spread goat cheese filling evenly over chocolate batter in pan. Spoon the remaining chocolate batter in small mounds over the goat cheese filling. Drag a thin metal spatula or table knife through chocolate batter mounds to marble the mixture.
Bake in the preheated oven about 45 minutes or until center is set. Cool in pan on a wire rack.
If desired, frost brownies with Honey and Cream Cheese Frosting. Using the edges of the foil, lift uncut brownies out of pan. Cut into bars.
In a large bowl combine cream cheese and butter. Beat with an electric mixer on medium speed until smooth. Gradually add 2 cups powdered sugar and honey; beat until combined. Add another 1 cup powdered sugar and milk, beating until smooth.