In a large microwave-safe bowl, combine the almond milk and 3 tablespoons. Place it in the microwave and heat on 30 second increments, stirring after each increment, until the butter has melted. Let the mixture cool just a tad and then sprinkle the yeast on top. Allow the yeast to activate for ten minutes (it will start to foam slightly) and then sprinkle on the sea salt and 2 tablespoons sugar.
Add a cup of the flour to the mixture and stir together. Add the second cup of flour and stir together. The dough will become significantly hard to stir. The dough should be sticky. If you find that the mixture is still too wet that you can't form it into a ball, add more flour until you get this sticky consistency. Once the dough becomes extremely difficult to stir, roll it out onto a floured surface. Knead the dough, adding flour as needed, for about 2 minutes, and then form it into a ball.
Transfer the dough to a well-oiled bowl and cover it with plastic wrap. Place it in a warm place to rise for an hour. After an hour, the dough should have doubled in size. If it hasn't doubled, let it rise for a longer amount of time.
Melt the rest of the butter (6 tablespoons) in a small saucepan or in the microwave. Preheat the oven to 350 degrees F and brush a 10 to 12-inch pan with a tablespoon of the butter. Roll the dough out onto a lightly floured surface and roll it out to a thin rectangle (about 1/2 inch thick). Taking 3 tablespoons of the butter, brush it onto the dough. Sprinkle the remaining sugar, cinnamon, and cardamom on top. Roll the dough into a log and place the seam down. With a sharp knife cut 8 equal pieces out of the dough. Place them evenly spread apart in the prepared pan.
Brush the remaining melted butter on top and place it on top of the stove to rise for about 5 minutes. Place it in the oven and bake the cinnamon rolls for about 25-30 minutes or until puffy and brown on top. Remove from heat and set aside to cool just slightly.
While the cinnamon rolls are baking, prepare your glaze. Combine the confectioner's sugar, almond milk, and salt in a small bowl. Whisk together until smooth. Add more confectioner's sugar or almond milk as needed.
Drizzle the glaze on top of the rolls and sprinkle with nuts if desired. Enjoy immediately!