For the Brownie:
1. Preheat the oven to 180°C. Lightly grease a 9" x 13" pan.
2. Combine the melted butter and sugar, stirring until smooth.
3. Stir in the cocoa, salt, baking powder and vanilla
4. Beat in the eggs one at a time. Then add the water, stirring until smooth.
5. Add the flour and chocolate chips, stirring until thoroughly combined.
6. Spoon the batter into the prepared pan.
7. Bake the brownies for 28 to 30 minutes, until a toothpick inserted into the center comes out clean, or with a few moist crumbs attached. The brownies should feel set both on the edges and in the center.
8. Remove the brownies from the oven, and cool them on a rack before cutting and serving.
For the Glaze:
1. Combine the butter and chocolate in a microwave-safe bowl and microwave on medium for about 1 minute. Stir and continue to heat for about 15 seconds at a time, stirring between intervals, until the chocolate and butter are melted and smooth.
2. Measure the icing sugar and then sift it into a small bowl. Stir the sifted powdered sugar into the melted butter and chocolate. Beat the mixture, adding small amounts of boiling water until thinned as desired. If you happen to find it too thin, add a little more icing sugar. If too thick, add more hot water.
3. Glaze over the cooled chocolate brownie then cut and serve with ice-cream