Preheat oven to 350°F. Spray a 9x5 loaf pan with nonstick cooking spray with flour, or grease and flour it.
Whisk flour, baking powder, and salt in a medium bowl. Set aside.
Mix melted butter and sugar together in a large bowl. Stir in eggs, one at a time, then stir in the pure almond extract. Add champagne and dry ingredients and stir until just moistened. Pour into prepared pan.
Bake for 35-45 minutes, or until a toothpick comes out clean. (Mine took about 45 minutes - so just keep an eye on it starting at about 35 minutes.)
While the cake is baking, heat the sugar and champagne for the glaze in a small saucepan over medium heat, until it boils. Boil for 1 minute, then remove from heat and set aside.
Once the cake is done, allow to cool for 15 minutes in the pan. Use a butter knife to loosen around the edges, then carefully remove the cake and place it on a cooling rack set over a cookie sheet or cutting board (something to catch the glaze and frosting drippings.) Use a pastry brush to generously brush the champagne glaze over the top of the cake. Let the cake finish cooling completely before frosting.
To make the frosting, whisk the powdered sugar, heavy whipping cream, 1 tablespoon of champagne and the teaspoon of rose water. Add more champagne as needed, to achieve your desired frosting thickness. I like mine fairly thick, but still easily pourable. Spoon the frosting over the top of the cake and spread to evenly coat. Allow to set, either at room temp or in the fridge (fridge is quicker, of course.)