In a large bowl, mix the melted butter, honey and warm water. Sprinkle the instant yeast on top and let it sit for about 5-10 minutes to bloom. Once you see bubbles on top, mix with a handheld whisk briefly.
Add the flour, and salt. If using a stand mixer, use the bread attachment and mix in medium to high speed for about 5 minutes until dough is elastic and smooth. If using a wooden spoon, just mix until the dough is well combined. Then continue kneading with your hand in the bowl until it's soft and elastic. Transfer to a lightly greased bowl and cover with cling wrap or tea towel. Prove for about 1 hour in a warm location like your pantry.
While dough is proving, prep your filling by soaking your pitted dates in warm water for about 10 minute. Transfer the dates, ripe banana, ground cinnamon into a food processor or blender and process til smooth and it turns into a paste consistency. If too dry, add a little of the date water.
Once dough has doubled, roll on a floured surface into a rectangle shape. Spread melted butter on the dough, and then spread on top of it the date paste. Roll the dough into a log starting at the edge closest to you, gently rolling tightly using both hands. Smoothen the edges and then cut into 1.5 inches thick using a twine or floss.
Transfer to a greased baking dish and spread the top of the buns with melted butter. Cover with plastic wrap or tea towel and let it prove for another 20-30 minutes. Pre-heat oven to 180 degrees Celsius and bake the buns once it's doubled in size for about 2-30 minutes.
Prep the glaze by mixing the powdered sugar and water. Drizzle on the buns before serving. Enjoy while warm.