Make the dough: Mix all the ingredients except the butter in a kitchen aid stand mixer with paddle attachment until the flour is evenly moistened and the dough has formed a cohesive, sticky mass, 2 to 3 minutes on low speed of a stand mixer.
Gradually add butter and incorporate about 1 minute on low speed. Once all the butter is incorporated, turn the mixer up one speed and knead the dough until it is smooth and supple though still somewhat soft and tacky, about 2 to 3 minutes.
Cover the dough and let it rest in a warm (75°F) place for 8 to 12 hours. To develop strength in the dough, stretch and fold it in the bowl three to four times during the rest. This will increase the elasticity of the dough.
Turn the dough out onto a lightly greased or floured work surface and gently deflate it. Divide the dough into Four 173g piece each.
Spread each dough into 10-inch circle. Place dough on a lightly floured work surface.
Place the bottom circle on prepared baking sheet. If it lost its circle shape, use your hands to form the edges back into a round shape. Top with filling about ¼ cup raspberry fruit spread, leaving 1/2” of exposed dough along edges. Then layer the remaining circles and filling on top.
The top layer does not have filling on it, so only 3 of the 4 circles will be topped with filling. Using a sharp knife or pizza cutter, cut any scraps around the edges so you have an even circle. Place a 3-inch round object or bowl in the center and make an indent.
This is the center of the star. Now it is time to cut strips from the edge to the center 3-inch circle. Using a pizza cutter, cut 16 even strips. Using both hands, grab two strips and twist them away from each other twice, then press the two ends together to make a point. Your star bread will have 8 points.
Cover the shaped bread with plastic wrap or aluminum foil and let it rest for 20 minutes.
Preheat oven to 400 °F (204°C).
Bake the bread: Using a pastry brush, lightly brush the star bread with egg wash. This ensures a beautifully shiny golden-brown bread. Bake for about 20 minutes or until golden brown on top. If you notice the top or points browning too quickly, loosely tent the star bread with aluminum foil. Remove from the oven and cool for 5 minutes.
To bake the same day: Bake the buns in a preheated 400°F oven for 22 minutes, until golden. A digital thermometer inserted into the center of a middle bun should read 190°F/ 87°C.
Dust confectioners’ sugar on top and enjoy warm.
You can cover and store leftover star bread at room temperature for 1-2 days or in the refrigerator for 4-5 days. For long time use you can freeze them.