Preheat the oven to 350 degrees

Grease and line a 8” round metal cake pan with parchment. Set aside

In a large mixing bowl, add the butter and chocolate. Melt butter and chocolate in the microwave, stirring every 30 seconds until melted

Add sugar, salt, and vanilla into the chocolate mixture mix until evenly combined

Add eggs one at a time and and mix until evenly combined

Add cocoa and mix until evenly combined

Cook for ~35 minutes until puffy on the edges but jiggly in the middle

Let it cool for at least 4 hours or overnight