Melt the chocolate and butter in a double boiler.
Whisk the eggs and slowly temper in the melted chocolate and butter mixture.
Add the water and vanilla paste.
Combine the sugar, flour, cocoa powder, powdered sugar, and salt in a separate bowl.
Pour the chocolate, butter, and egg mixture into the dry ingredients and fold until fully combined.
Grease a parchment-lined baking pan with softened butter.
Pour the batter into the prepared pan and sprinkle the top with chocolate chips.
Bake at 325°F for 45 minutes or until the internal temperature reaches 200°F.
Let the cake cool, then remove it from the pan.
Optionally, warm the cake to create a molten lava cake effect.
