Prepare the ganache first by placing the chocolate chips and heavy cream in a small owl. Microwave until melted, stirring every 30 seconds.
Once melted, add in the vanilla and stir, then cover and place in the fridge. This needs to be refrigerated for at least 30 minutes so that it solidifies a bit to be able to be placed into the middle of the batter later.
To prepare the lava cake, add the melted butter, powdered sugar, dry milk, and vanilla to a small bowl and whisk together. Set aside.
Add the egg, egg yolk, brown sugar, and pumpkin puree in a large bowl and whisk together. Pour in the melted butter mixture and whisk together. Then add the flour, pumpkin pie spice, and salt and whisk until combined.
Coat your two ramekins very well with some butter and flour. Pour the lava cake mixture evenly into both ramekins.
Then remove the ganache from the fridge and divide it evenly between the two ramekins, spooning it into the middle of each ramekin filled with the lava cake mixture. Then, cover any exposed ganache with the lava cake mixture using a spoon. Cover and refrigerate for 15 minutes.
Preheat the oven to 320 degrees F for 3-5 minutes. Place teh cake into the air fryer and set cook time for 8-10 minutes.
Remove and serve with your favorite toppings!