To a bowl, add the warm milk and whisk in the sugar and yeast. Allow to sit for 3-5 minutes (maybe more) until to start to see it bubble.

To a mixing bowl add the flour, salt, cinnamon, ginger and dried blueberries, mix well. 

Make a well in the center of the flour mix, add the milk and yeast, butter, eggs and lemon zest. Use a spatula to mix until the dough comes together, then use your hands to make the dough to a large ball. It will be sticky. Turn the dough out on to a floured surface and knead for about 5 minutes, until smooth and elastic, adding small amounts of flour as needed until smooth and no longer sticky. The dough is ready when you stretch a small piece between your fingers and it thins out without tearing. You can also press your finger lightly into the dough—if it springs back slowly, it's ready.

To make the dough ahead: You can refrigerate the dough after step 4, wrap well and refrigerate, or complete step 7 and refrigerate the shaped buns, cover and refrigerate. In both cases, allow the dough to come to room temperature before continuing with the recipe. Add the crosses right before baking.

Cover a large baking sheet/tray with parchment paper.

Once risen, divide the dough into 12 balls and shape each into a bun. You can weigh them to get them all the same size if you have a scale. Place close together on the baking sheet/tray and cover loosely with a towel.  Leave in a warm place for 30 minutes until doubled in size and touching.

Preheat oven to 400°F /200°C.

Mix the ⅓ cup flour, sugar and lemon zest. Mix well and add enough warm water to create a thick paste. Add to a ziptop bag, remove the air and seal. Cut a little off the corner off the ziptop bag and pipe a cross on top of each bun. You can also use a piping bag. No need to score the dough, the crosses melt into the the buns as they bake.Bake for 20-25 minutes until golden brown (time will depend on your oven).

Add the powdered sugar to a small bowl with 1 tablespoon warm water and stir until syrupy. Remove the buns from the oven and brush with the glaze while still warm. Cool the buns on a wire rack.

To store the baked buns, keep in an air tight container for up to 4 days. If you find the buns getting too firm, I like to microwave them (one at a time) for about 10-15 seconds, this will soften them up and also make them nice and warm. You can also warm them in a preheated oven to 300°F (150°C). Wrap the buns in foil and warm for 10–15 minutes. You can also, cut them in half and lightly toast them.