Sweetened Condensed Milk Dough Filled Cookies

The following tasty cookies were inspired by THIS blog post. Though the cookies looked very tasty, I was mostly intrigued by the dough, which listed condensed milk as one of the ingredients. The use of condensed milk in pastry dough was new to me, and I wanted to give this unique dough a try.
I had no doubt the sweet bean paste and mochi (sweet rice) filling was just as delicious, however, I decided to substitute it with a mixture that was quicker to prepare. Since the dough is fairly sweet, I opted for a filling that will not make the cookies overly sweet. I mixed some cooked prunes, chopped walnuts, a bit of maple syrup, powdered sugar, and dark cocoa,  and liked the result.
A couple of other changes I’ve made were to create smaller cookies, and to roll the dough and cut it with a cookie cutter, rather than shape each cookie by hand. The dough was smooth and easy to work with, and filling it and rolling into small balls was quick and easy.
The baked cookies were simply delicious. The dough was soft and silky, yet firm enough to hold the filling and keep its shape while baking. The filling gave just the right contrast, with its dark color, slight bitter flavor from the cocoa, smooth prune paste and crunchy walnuts. Served with coffee or tea, the cookies make for a tasty snack any time of the day. Try them and enjoy.

Makes: 22-24 cookies
Prep time: 20 minutes
Chilling time: 30 minutes and up to overnight
Baking time: 20-25 minutes

Ingredients:
For the dough: (inspired by THIS blog)
1 L egg, at room temperature
½ cup condensed sweetened milk
1½ cups flour
1 tsp baking powder
¼ tsp salt
For the filling:
10 large pitted prunes
¼ cup water
2 Tbs maple syrup
¼ cup powdered sugar
1 Tbs dark cocoa powder
1 cup walnuts, finely chopped
For the egg wash:
1 egg yolk, mixed with 1 tsp water

1. The dough: in a medium size bowl, whisk together the egg and condensed milk. Add the flour, baking powder and salt, and mix with a spatula (the dough is quite sticky at first). Knead briefly (add flour , if needed, but  as little as possible), and wrap with wax paper. Refrigerate for at least 30 minutes and up to overnight (which is what I did).

2. The filling: place the prunes, water and maple syrup in a small pot, and bring to the boil. Lower the heat and cook until most of the liquids evaporate. Blend with a hand blender to a smooth paste. Add the powdered sugar, cocoa and walnuts, and mix well.

3. Preheat the oven to 340F (170C). Line a cookie sheet pan with baking paper.
4. Divide the chilled dough into two equal portions. Roll each portion, on a lightly floured working space, to thickness of about ¼” (0.6cm). Using a 2.5 inch (6.35cm) cookie cutter, cut out 9 discs from each portion. Briefly knead the scrapes together, roll them again, and cut 4-6 more discs. Place a heaped teaspoon of filling in the center of each disc, and fold the dough over it, to create a filled ball. Place the balls in the pan and brush the tops with egg wash.

5. Bake for 20-25 minutes, until the tops and bottoms are golden. Place on a rack, to cool to room temperature, before serving.