1 cup (2 sticks) butter or margarine or butter
4 (1 ounce) squares unsweetened chocolate
4 (1 ounce) squares semisweet chocolate
2 1/4 cups granulated sugar
6 large eggs
2 teaspoons vanilla extract
1/2 teaspoon salt
1 1/4 cups all-purpose flour
Praline Topping (below)
1/2 cup pecans, toasted and coarsely chopped

Preheat oven to 350 degrees F. Line a 13 x 9-inch metal baking pan with foil; grease foil.

In heavy 3-quart saucepan over low heat, melt margarine or butter and chocolates, stirring frequently. Remove saucepan from heat. With wire whisk, beat in sugar, then eggs, until well blended. Stir in vanilla extract and salt. Stir in flour just until blended. Spread batter evenly in pan. Bake 35 minutes (wooden pick inserted in brownies will not come out clean). Cool brownies in pan on wire rack. If not using brownies within 1 day, cover cooled brownies with foil and refrigerate or freeze for longer storage.

Prepare Praline Topping. With metal spatula, spread topping over room-temperature brownies; sprinkle with pecans. Cut brownies lengthwise into 8 strips, then cut each strip crosswise into 8 pieces.

Praline Topping
5 tablespoons butter or margarine
1/3 cup firmly packed light brown sugar
3 tablespoons bourbon (or 1 tablespoon vanilla
    extract plus 2 tablespoons water)
2 cups confectioners' sugar

In 2-quart saucepan over medium-low heat, heat butter or margarine and light brown sugar, until mixture melts and bubbles, about 5 minutes.

Remove saucepan from heat. With wire whisk, beat in bourbon or vanilla extract-water mixture. Beat in confectioners' sugar until mixture is smooth.