Turn on the instant pot and select sauté.
Add butter, sugar in the inner pot and let butter melt.
After melting, add in milk and vanilla extract.
Whisk well until it is smooth and starts to simmer.
Pour ½ cup of this mixture in a bowl.
Add in baking soda, flour, eggs in it.
Mix well and keep it aside.
Return to instant pot and close its lid.
Set the instant pot to “Manual” at low pressure for 30 minutes, release the pressure naturally for 15 minutes while switching it to warm.
Dish out cake and drizzle the mixture in the bowl on it.
Serve and enjoy.