Easy chocolate brownie

I wanted to share with you my easy chocolate brownie recipe. Its very chocolatey, very decadent and really not good for you at all (...but you need some of that type of stuff now and then!) and best of all does not require any wacky ingredients.
Back before the studying full time gig I used to make this all the time and even I - the non cook in the house - managed to get it right the first time.

Of course now, oddly, since wanting to post this recipe I have made this twice and I have screwed it up. Well - It still tasted yummy but it was not quite as good textured as usual so I've added some learning experiences at the bottom of this post.

Ingredients:
170g or about ¾ cup butter
1+½ cup sugar
2 teaspoons of vanilla essence
3 eggs
¾ cup all-purpose flour
½ cup cocoa powder
1 teaspoon baking powder
pinch of salt (optional)
handful or two of chocolate dots OR
chopped pecans or walnuts (optional)
Icing sugar for dusting

Method:

• Preheat oven to 180 deg C or around 160ish deg C if you fan force (about 350F).
• Line a 33 x 23 cm cake tin with grease proof or other non-stick paper and grease the tin. 
• Melt the butter.
• Beat eggs with sugar. Add vanilla, flour, cocoa, baking powder, salt if you wish and the melted butter.
• Here I usually add a few handfuls of chocolate dots because I love my brownie super chocolatey and if I'm going to eat bad stuff I might as well do it well, but you can add nuts if you wish and pretend its semi healthy or something.
• Bake at 180 degrees C in center of oven until a wooden pick inserted in center comes out clean. This can be approximately 20-30 minutes but I usually check it around 15-20 and keep checking it every few minutes after.

Ok... how not to screw this up:
1. Like with any baking - measure correctly. The first time it got screwed up I had ZJ helping me and the measuring was a bit haphazard.
2. dont heat up the butter too much, melt it JUST.
3. Know your oven - we moved since I baked this the 4937543 times and I'm not used to this oven. Make sure to also bake it bang on in the middle or closer to the bottom if anything. I find it need to have it lower if its fan forced - around 150 deg C and leave it for longer, around 40 minutes. I just kept checking it ever 5 though.