Place the flour, sugar, yeast, and salt in a sizable bowl or the bowl of a stand mixer, and stir. In a well, combine the milk, honey, egg, oil, vanilla bean paste, and orange or lemon zest. Blend until dough forms. The dough should be smooth, soft, and elastic after 7-8 minutes of kneading.
Put the dough in a bowl that has been lightly greased, cover it, and let it rise for approximately an hour or until it has doubled in size.
Form each of the X (80g) pieces of dough into a ball. Place the balls on a baking sheet covered with parchment paper, giving them room to rise between each one. Allow to rise for about an hour, covered with a fresh towel, until it has doubled in size.
Preheat oven to 350F (180C).
1 egg and 1 tablespoon milk are whisked together in a small bowl. Apply egg wash to each bun.6. Bake the buns until golden brown, about 15 minutes.
Allow to cool completely.
Whip heavy cream, vanilla extract, and powdered sugar in a big bowl to make the cream. Whip until firm peaks appear. Place in a piping bag.Cut each bun only across the top; leave the base intact. The cream should be used to fill and smooth each bun.
Top each bun with powdered sugar and serve with hot tea.