Bunny (1998)

Bunny, an elderly rabbit who uses a walker, is in her kitchen one night baking a cake. A photograph from her wedding day is on her wall. A pesky and persistent moth bangs about the kitchen. She shoos it outside, turns off the porch light, and returns to her baking. The moth finds its way back into the kitchen, she bats it with a wooden spoon, and it falls into the mix. She stirs it up, pours the batter into a pan, and pops it into the oven. But the moth isn't done: it has a different mission, turning the oven into a portal, and inviting Bunny on a voyage of reunion.

Unfortunately the movie Bunny is not yet available on HBO Max.