Blueberry Muffin Cookies

Add the brown sugar to a medium sized mixing bowl. Zest the lemon into the mixing bowl, then use your fingers to rub the zest into the sugar.
Add in the butter, then use a hand or stand mixer to beat the mixture together until it's light and fluffy (~2-3 min.)
Add in the egg yolk, greek yogurt, and vanilla, and beat until well combined (~1 min.)
Add in the flour, baking powder, and salt. Use a rubber spatula to fold the ingredients together until only a few streaks of flour remain.
Add in the blueberries, and do a couple of big gentle folds in the dough. Then, dollop the blueberry jam in random areas over the dough, and do another couple of big gentle folds. (We don't want the blueberry jam completely cohesive with the dough here!)
Cover the bowl then place in the freezer to chill for 30 minutes. In the meantime, make the streusel.

Add the butter, sugar, flour, and cinnamon to a small mixing bowl. Use a fork or your hands to combine the ingredients until you have little clumps of dough.
Cover the streusel and place it in the fridge to chill until you're ready to bake the cookies.
Once the cookies have chilled, preheat the oven to 350°F / 175°C. Line a cookie sheet with parchment paper or with a silicone baking mat.
Use a 3 tbsp. cookie scoop to dish out the cookies. Press the tops of the cookies gently into the bowl of streusel. Then, place the cookies onto the prepared cookie sheet, evenly spacing them ~2" apart to allow room for spreading.
Bake for 13-15 minutes, until the sides of the cookies start to turn golden brown. Let the cookies rest on the hot baking sheet for at least 5 minutes before transferring them to a wire rack to cool. Serve and enjoy!