Microwave the 1 1/2 cup plant milk for 60-90 seconds until it's warm like bathwater.
Combine the plant milk, 2 1/4 tsp yeast, and 1/4 cup granulated sugar in a stand mixer and whisk to combine.
Add 1 cup all-purpose flour, 1/3 cup melted butter, and 1 tsp salt into the stand mixer and mix on low until combined.
Add 3-4 cup all-purpose flour into the stand mixer, starting with just 3 cups, only adding more as needed. Mix until it clears the sides of the bowl. You want the dough to be tacky but workable.
Knead using the stand mixer for another 2 minutes.
Place the dough in a large bowl (greased) and cover with plastic wrap.
Let rise for 1-2 hours.
Preheat the oven to 350 ºF.
Spray your cooking pan with non-stick spray. The traditional shape uses a bundt pan, but cake pans or oven-safe glass bowls are other good options.
Whisk the 1 cup dark brown sugar, 3/4 cup granulated sugar, and 1 tbsp cinnamon in a small bowl.
Put the 3/4 cup melted butter in another small bowl.
Roll the dough out into a square that's about 1" thick. Then, cut the dough into roughly 64 pieces (AKA an 8x8 grid, hence the square). If the pieces are different sizes or you have less than 64, that’s ok.
For each piece: Roughly roll it into a ball, coat in butter, coat in sugar, place in your pan.
(If preparing ahead of time, stop here and place your pan in the fridge overnight. Before baking, let it warm to room temperature.)
If you have any remaining melted butter, feel free to drizzle it over everything.
If your pan is looking pretty full, I highly recommend placing it on a baking sheet before putting it in the oven. This will rise quite a bit, which may cause hot sugar to spill out.
Bake for 30-35 minutes.
Let sit for 10-15 minutes.
Before serving, turn it upside down onto a serving plate. Enjoy!