Step 1: Warm the plant milk to about 105-115°F (40-46°C). In a large bowl, combine the warm milk, yeast, and 1 teaspoon of the granulated sugar. Stir gently and let sit for 5-10 minutes until foamy.
Step 2: Add the remaining granulated sugar, melted vegan butter, vanilla extract, and salt to the yeast mixture. Mix well. Gradually add the flour, 1 cup at a time, mixing until a shaggy dough forms.
Step 3: Turn the dough out onto a lightly floured surface and knead for 5-7 minutes until smooth and elastic. If the dough is too sticky, add a little more flour, one tablespoon at a time.
Step 4: Lightly grease a large bowl with vegan butter. Place the dough in the bowl, turning to coat. Cover with a clean kitchen towel or plastic wrap and let rise in a warm place for 1-1.5 hours, or until doubled in size.
Step 5: While the dough is rising, prepare the filling. In a medium bowl, cream together the softened vegan butter, brown sugar, and ground cinnamon until smooth.
Step 6: Once the dough has doubled, punch it down gently and turn it out onto a lightly floured surface. Roll the dough into a large rectangle, about 12×18 inches (30×45 cm).
Step 7: Evenly spread the cinnamon filling over the entire surface of the dough, leaving a small border at one of the long edges.
Step 8: Starting from the long edge opposite the border, tightly roll up the dough into a log. Pinch the seam to seal it.
Step 9: Using a sharp knife or a pizza cutter, slice the log into 12 equal pieces (about 1.5 inches or 4 cm thick).
Step 10: Arrange the cinnamon rolls in a lightly greased 9×13 inch (23×33 cm) baking dish. Cover again and let rise in a warm place for another 30-45 minutes, or until puffy.
Step 11: Preheat your oven to 375°F (190°C). Bake the rolls for 20-25 minutes, or until golden brown and cooked through.
Step 12: While the rolls are baking, prepare the frosting. In a medium bowl, beat together the softened vegan cream cheese and vegan butter until smooth. Gradually add the powdered sugar and vanilla extract, beating until creamy. If needed, add 1-2 tablespoons of plant milk to reach desired consistency.
Step 13: Once the cinnamon rolls are out of the oven, let them cool for 5-10 minutes. Spread the vegan cream cheese frosting generously over the warm rolls. Serve immediately and enjoy!