Method
1. Pre-heat oven - 160°C
2. Grease a clean round pan
3. Add unsalted butter, powdered sugar, peanut butter, salt and vanilla extract to a clean medium bowl
4. Mix until blended
5. Add all purpose flour, baking powder and salt to a clean medium bowl
6. Add unsalted butter and dark chocolate to a clean medium glass bowl
7. Melt in microwave - low heat
8. Add granulated sugar to the batter
9. Whisk until combined
10. Add egg to the batter one by one while mixing
11. Transfer dry ingredients to batter
12. Mix until well combined
13. Transfer batter to round pan
14. Bake until skewer tests clean - 40 min, 160°C
15. Let cool