How do I warm up my baby's cup/beaker?

Hi I stopped breastfeeding around 11m and have been giving Oat milk to my LO in a beaker from Sainsbury's pictured. Luckily the weather has been warm and she prefers colder milk so I've just been pouring straight from the fridge to give to her. However it's getting colder and especially if she wakes in the morning or during the night I want to give her warmer milk. Any tips for warming it up quickly so she doesn't scream the house down waiting?? I have the Tommee Tippee travel bottle warmer which I fill with boiling water before going to bed, and pour into a bowl to warm the cup (due to it being too wide for the lid thing), but by morning the water isn't that hot so it doesn't really warm the milk. Also boiling a kettle to site the cup in is also time consuming... are there any other ways?