Cake
1 cup butter, softened
1 cup brown sugar, firmly packed
2/3 cup granulated sugar
2 teaspoons vanilla extract
1/2 teaspoon salt
4 eggs
2 cups all-purpose flour
1 package chocolate chips, "Little Bits" semi-sweet,
    divided (12 ounce pack)

Frosting
3/4 cup butter, softened
1 1/2 cups sifted confectioners' sugar
2 teaspoons vanilla extract

Cake: Preheat oven to 350 degrees F. Grease 15 1/2 x 10 1/2 x 1-inch jellyroll pan. Line with wax paper.

In bowl, cream butter, brown sugar, sugar, vanilla extract and salt. Add eggs, one at a time, beating well after each addition. Gradually add flour. Stir in 1 cup chocolate bits. Spread in prepared pan. bake 20-25 minutes. Cool completely. Loosen sides of cake. Invert onto floured cloth. Peel off wax paper. Cut cake crosswise into four 3 3/4 x 10-inch sections. Spread 3 slightly rounded tablespoons frosting on one layer. Top with second layer. Repeat layers. Frost with remaining frosting.

Frosting: Melt over hot (not boiling) water, 1 cup semi-sweet chocolate bits, stir until smooth. Set aside.

In bowl, cream butter and confectioners' sugar. Add melted chocolate and vanilla extract; blend until smooth.