Break up the chocolate into a saucepan or a microwave safe bowl and add in the cubed butter. melt over a low heat until melted and stir constantly. You can do this in the microwave for 2½ minutes on medium and stir a few times.
Add in sugar and mix well.
Add in the eggs and mix well
Add in the sifted flour and baking powder and really mix well.
Pour into a lined square baking tray (not too big) and bake in a 180 degrees oven for about 20 minutes. If your oven runs hot/fan forced drop the temperature by 5-10 degrees.
When a knife comes out clean you are done. Leave to cool in tin and then remove by the paper and slice and enjoy
Recipe by Retro Mummy at https://retromummy.com/2015/08/01/best-ever-chocolate-brownies-for-a-small-family-or-a-big-crowd/