Zest the oranges: Zest the oranges and divide into two piles (one for the dough and one for the icing.) Set aside.
Combine the liquids: Combine the plant milk and orange juice. Mix well and set aside. Slowly melt the butter in a saucepan over low heat or in the microwave. (Be careful not to heat it, you just want to warm it enough to melt.) Combine the melted butter and vanilla to the milk mixture and stir to combine. Set aside.
Make the dough: In a separate large bowl, whisk together the flour, sugar, yeast, salt, orange zest, allspice, nutmeg, and clove (if using). Use your hands to break it all up and incorporate the zest into the flour. Pour the liquid mixture into the bowl with the dry ingredients and use a wooden spoon to bring the mixture together into a shaggy dough.
Knead the dough: Turn the dough out onto a clean dry surface. Knead the dough for 5-7 minutes until it forms a smooth ball. DON'T be tempted to flour the surface, the dough will be very sticky at the start but it will come together once ready. If it gets too messy, you can wash and dry your hands halfway through the process. A dough scraper is also very useful to frequently scrape up any dough that sticks to the surface.
1st proof: Clean and dry the bowl and lightly grease it with some plant butter. Place the dough ball into the bowl and cover the top of the bowl tightly with plastic wrap. Place in a warm part of your kitchen to proof for 1-2 hours until the dough has puffed up and doubled in size.
Roll the dough: Punch the air out of the dough. Then roll it out on a lightly floured surface into a large rectangle (about 11 x 16").
Make the filling: In a small bowl, combined the softened butter, brown sugar, and cinnamon. Use a fork to mash and mix together until fluffy and thoroughly combined. (It needs to be soft and spreadable or you will tear the dough!)
Spread the filling: Using a butter knife or offset spatula, carefully spread the filling in a thin layer over the dough, going all the way to the edges. Carefully and tightly roll the dough into a log. Mark the log into 9 portions. Using a sharp knife or unflavored tooth floss, cut them into sections.
2nd proof: Place the rolls in a baking dish (I used a 9 x 13" but you could also use a 10.5 x 7.5") and then cover with plastic wrap. Let them proof in a warm place for 1-2 hours until they rise and double in size. (Alternatively, to make overnight cinnamon rolls, you can place them in the fridge for up to 24 hours at this stage. Then take them out to sit at room temperature for about 2 hours, or until they double in size. You can also put them in the freezer and take them out around 4 hours before baking. Please refer to the blog post copy for more details.)
Bake the rolls: Preheat the oven to 350°F (175°C). Bake for 20-30 minutes until the tops are light golden brown. Cool slightly for 15 minutes before adding the icing.
Make the icing and glaze the rolls: In a small bowl, whisk together the powdered sugar, orange juice and zest, vanilla, and salt. (At this point you can add more juice or powdered sugar until the desired texture is reached. It should be quite thick and creamy!) Drizzle the icing on top of the warm buns, using the back of a spoon to spread it out evenly.
Enjoy or store: Enjoy the rolls immediately or, once cooled, place them into an airtight container. They will keep at room temperature for 2 days, or you can refrigerate them for up to 5 days. Take them out of the fridge an hour before serving to let them soften.