In a mixer bowl activate the yeast by adding the yeast, milk and sugar. Let the mixture foam for about 15 minutes.
In a separate bowl add together the flour, salt and vanilla extract. Set aside
Once the yeast is activated add the dry ingredients together with the egg to the mixer bowl. With a hook attachment knead the dough for about 3 minutes, until a soft dough starts to take shape.
Then gently add the diced butter one piece at a time until all the butter is incorporated. Let the dough knead for about 10 minutes. Make sure it passes the windowpane test*.
Cover the dough and let it rest for an hour in the warmest place in your kitchen until it doubles in size.
Line a large baking tray with parchment paper and dust it with flour. Set aside
Once the dough is doubled in size, transfer it to a well floured surface. Divide the dough into 8 equal parts, form into balls and cover.
Flatten each dough ball down slightly and roll it into a sausage shape about 10cm long. Repeat until all buns are ready. Place the buns on the prepared tray keeping a good amount of space between each one. Cover and let rise for another 30 minutes.
Preheat the oven to 180°C or 350°F while the buns are rising.
Before placing the buns into the oven, brush them with the egg wash.
Bake in the oven for about 15 minutes, until the bun have a nice golden brown colour.
Once baked, let them rest for a couple of minutes before filling with the cream and jam.