Add all dough ingredients to the bowl of a stand mixer fitted with a dough hook.

Mix on low speed for 2–3 minutes until combined.

Increase to medium speed and knead for a total of 12 minutes, until smooth and elastic.

Transfer to a lightly greased bowl. Cover with plastic wrap and place in a warm place to rise for 1 hour.

Punch down and allow to rise for another hour.

In a small bowl, stir together softened butter and lemon juice until smooth.

In a separate bowl, combine sugar and lemon zest. Rub together to release the oils.

Turn dough onto a lightly floured surface.

Roll into a 10 x 12 inch rectangle.

Spread the lemon butter evenly over the surface.

Sprinkle lemon sugar over the top and gently press into the butter.

Roll tightly lengthwise into a log.

Slice the log in half lengthwise with a sharp knife.

Twist the two halves together, keeping cut sides facing up.

Place into a parchment-lined 9x5 prepared loaf pan.

Cover loosely and allow to rise 45–60 minutes until slightly puffy.

Whisk together egg, salt, and water. Brush gently over the top of the dough.

Bake at 350°F for 30–35 minutes, or until golden brown and the internal temperature reaches 190°F.

If browning too quickly, tent loosely with foil.

Lemon Syrup Finish

While baking, stir together lemon juice and powdered sugar until dissolved.

As soon as the babka comes out of the oven, brush or pour syrup over the hot loaf.

Cool in pan 10–15 minutes, then transfer to a wire rack to cool completely.

Store fully cooled babka in an airtight container at room temperature for up to 3 days.