[For Filling]
Put frozen strawberries and granulated sugar in a small bowl. Heat it in a microwave at 600W for two minutes. Stir once, heat for another two minutes, add rum and stir. Set it aside to cool.

Put frozen pineapples and granulated sugar in a small bowl. Heat it in a microwave at 600W for one and a half minutes. Stir once, heat for another 1.5 minutes, add rum and stir. Set it aside to cool.

[For Custard]
※Preparation
・Grease two square baking dishes with butter.
・Melt unsalted butter in a microwave.
・Put soy milk and heavy cream in a small pot. With stirring, warm it on medium heat for around 5 minutes until 40℃ / 104 F.
・Preheat an oven to 190℃ / 374 F.

Put granulated sugar, cake flour, and salt in a large bowl and stir well.
Break eggs into it and use a whisk to stir well until you don’t see any flour left.

Add the warmed milk mixture in 4 batches and stir well until smooth each time.
Add vanilla bean paste, and stir well. Add the melted butter, and stir well for 1 minute.

With straining with a tea strainer, pour it into each baking dish. Use a spoon to drain strawberries and pineapples, and add to the batter evenly.

Lower the oven to 170 ℃ / 338 F and bake for 45 minutes until golden brown.
Remove from the oven and let it cool for around 20 minutes. It will slowly go down.
Lightly sprinkle powdered sugar on the top and done!

It tastes good while it's warm or even when chilled in a fridge.
Cover it with plastic wrap to prevent drying if you put it in the fridge.