Preheat oven to 180 C and line a tube pan or bundt pan with butter and dust with dry flour.
Boil water in the kettle. Pour a cup of hot water in a bowl or jar and add the celestial nutcracker sweet tea bags.Let the tea brew for a minute.Once brewed remove the tea bags.
In a mixing bowl sift flour, baking powder, baking soda and salt.Whisk with a balloon whisk until combined.
In a microwave, safe bowl melt butter for 30 seconds or until it starts melting.
In another mixing bowl add condensed milk. Pour warm butter over it and whisk to combine. Finally, add one cup of fresh brewed tea and buttermilk and whisk again.
Add the flour into the wet ingredients in two to three batches, folding the ingredients gently.
Pour the batter into the prepared pan.Tap it on the counter to remove any air bubbles.
Bake in preheated oven for about 30 to 40 minutes or until a toothpick or skewer inserted in the centre of the cake comes out clean.
Remove the cake from oven. Invert the cake on wire rack, cool completely before icing.
For Icing
Combine all the ingredients for icing in a small bowl.Pour the icing over cooled cake.
Slice and serve. Enjoy the cake with a cup of tea.