Preheat the oven to 350F. Line a baking sheet with parchment paper. Set aside.
In a stand size mixer fitted with the paddle attachment, cream the butter and both sugars together until light and fluffy. About 3 minutes.
Add in the egg and egg yolk and continued to beat on medium speed for about 1 minute. With a rubber spatula, scrape down the sides and the bottom of the bowl.
Add the molasses and vanilla extract, mix on low just until incorporated
On the lowest speed, add the flour, salt, baking powder, cinnamon, and ginger. Mix just until there are no more flour streaks.
Using a large cookie scooper, I used 3 tablespoon size scoop and smushed two together to make them larger. Scoop out 10 equally sized cookie dough balls. Place them on the prepped baking sheet, and place them in the fridge while you make the crumb topping.
For the topping
In a medium-size bowl, using your hands, mix all the ingredients until they are combined and have a “shaggy” look. There should be no flour streaks.
Once the crumb topping is done, coat the top of the cookies with the crumb until they are completely covered. Really press the streusel into the dough.
Bake for 14-16 minutes, while they are baking make the drizzle by combing both ingredients and mixing until incorporated
Once the cookies are done, let them slightly cool and drizzle with the icing.