01 - Combine flour, sugar, yeast, and salt in stand mixer bowl.
02 - Add eggs and lukewarm milk. Mix on low speed with dough hook until shaggy dough forms.
03 - Increase to medium speed, kneading for 5 minutes. Gradually incorporate softened butter cubes until dough becomes smooth and elastic, approximately 10 minutes.
04 - Transfer dough to lightly greased bowl, cover, and let rise in warm area until doubled, about 1 to 1.5 hours.
05 - Line 9x5-inch loaf pan with parchment paper.
06 - Punch down dough and roll on floured surface into 10x16-inch rectangle.
07 - Spread raspberry jam evenly over dough, leaving 1/2-inch border. Sprinkle with crushed fresh raspberries if desired.
08 - Roll dough tightly from long side into log. Slice lengthwise down center, then twist two halves together keeping cut sides up.
09 - Gently transfer twist to prepared loaf pan.
10 - Cover and let rise until puffed, approximately 45 minutes.
11 - Preheat oven to 350°F.
12 - Whisk egg and milk together, brush over loaf.
13 - Bake for 30 to 35 minutes until golden brown and loaf sounds hollow when tapped.
14 - Cool in pan for 10 minutes, then transfer to wire rack to cool completely before slicing.