Prepare - Preheat the oven to 350 degrees and line a standard metal loaf pan (9×5 inches or 8 1/2x 4 1/2) with parchment paper for easy removal later.
Cinnamon sugar - In a small bowl, mix the brown sugar and cinnamon together. Set aside.
Bread - In a large bowl, whisk the soy milk, lemon juice, sugar, melted vegan butter and vanilla until well combined. Now add the flour, baking powder and salt and mix with a large spoon until just combined, being careful not to over mix.
Pour in pan with cinnamon swirl - Pour/spread half of the batter into the prepared pan. Reserve about 2 tablespoons of the cinnamon sugar for the top of the bread, and sprinkle the rest of the cinnamon sugar over the top of the batter in the pan. Spoon or pour the rest of the batter on top of the cinnamon sugar layer. Carefully spread it out the best you can without stirring the cinnamon sugar layer. Sprinkle the top with the rest of the cinnamon sugar. Using a butter knife, make a large swirl in the loaf. Avoid swirling too much or you won't get that pretty cinnamon swirl throughout the bread.
Bake - Place in the center rack of the oven and bake for 60-75 minutes, or until a toothpick inserted in the middle comes out clean with no wet batter.
Cool - Cool in the pan for about 30 minutes, then carefully remove from the pan using the parchment paper. Transfer to a cooling rack with parchment paper below (to catch the glaze drippings).
Glaze - In a small bowl, whisk the powdered sugar, cream and vanilla together until smooth. Drizzle the bread with the glaze and allow to set for 20 minutes or so if possible. Slice and serve.