Warm the milk. Aim for a cozy 36–42°C. If it gets too hot, just let it cool a little so it is comfortable.
In a microwave-safe bowl or on the stove, melt the vegan butter until soft and smooth. Take a moment to enjoy the smell.
Add the warm milk, sugar, and active yeast to a large bowl. Set it aside and watch the magic happen as the yeast wakes up and starts to bubble. It should look foamy and alive.
Add the melted vegan butter and flour to the bowl. Mix with a dough hook or a wooden spoon for 5 minutes until it comes together into a lovely, soft ball.
Add the softened butter to the dough and knead it in until fully combined. If kneading by hand, work it on a floured surface until smooth and silky.
Cover the dough with a tea towel or cling wrap so it is snug and cozy. Rest in a warm place for 2 hours. When ready, it should have nearly doubled in size. Look at it grow.
While the dough rests, make the custard. In a medium saucepan, whisk together sugar, cornflour, custard powder, vegan milk, vanilla, and agar agar if using.
Heat on medium and whisk constantly until it starts to boil and becomes frothy. The foam is normal and fun.
Once thickened, add the vegan butter and mix until smooth. Remove from heat and cover the surface with cling wrap to keep it silky.
Roll out 10 dough balls and place them on a lined baking tray. Cover again and let them rest for 45 minutes. They will puff up beautifully. Press a small well into the center of each ball.
Scoop the custard into the little wells evenly across all 10 buns.
Brush the edges with vegan plant milk to help them shine.
Add a tablespoon of blueberry jam on top of the custard.
Mix the crumble ingredients in a bowl and sprinkle a generous handful on top. Crispy, sweet, and perfect.
Bake in the oven for 20-25 minutes until golden and irresistible.
Take them out and let them cool on the tray for a few minutes. You can peek now.
Enjoy warm and cozy. Optional: mix the glaze ingredients and drizzle on top for an extra touch of sweetness.
These buns will stay fresh for 2-3 days in an airtight container, but honestly, will they last that long.