Preheat the oven to 400°F and grease two 8 oz. Ramekin (or two cavities in a jumbo muffin tin) with baking spray.
Place the chocolate chips, butter, and oil in a microwave safe bowl. Microwave in 30 second intervals and whisk together after each interval until the mixture is smooth.
In a larger mixing bowl, whisk together the brown sugar, eggs, and vanilla until combined.
Pour the melted chocolate mixture into the egg and sugar mixture, whisk together until smooth.
Next, add the flour, salt, cocoa powder, and espresso powder and whisk until combined or until no dry ingredients remain.
Divide the batter evenly between the two ramekins.
Place the ramekins on a sheet tray and bake for 10 minutes.
While the cakes are baking, use a cookie scoop or tablespoon to scoop the ganache centers and roll into balls. Set aside in the freezer until ready to add to the center of the lava cakes.
After the first 10 minutes of baking time, pull the cakes out of the oven and gently press the ganache balls into the middle of the cakes. Use the back of a spoon to cover the ganache balls with cake batter.
Bake cakes for another 5 minutes.
Once the cakes have finished baking, immediately invert the cakes onto a plate once they come out of the oven.
Top with your choice of powdered sugar, whipped cream, fresh berries, or vanilla ice cream. Or let’s be honest, all of the above and enjoy!