Preheat oven to 350°F. Line a baking sheet with parchment paper and set aside.
In a large mixing bowl add cake mix, brown sugar, cinnamon, and oats, stir until well combined.
Add eggs and vanilla and stir until dough is formed.
Roll dough into 10 even balls about 2 inches in size.
Place dough balls on the prepared cookie sheet and press down to flatten.
Bake for 12-14 minutes or until golden brown along the edges.
Let cookies cool on the baking sheet for 2-3 minutes before transferring to a cooling rack.
While cookies are cooling, prepare your crumb topping.
In a small bowl whisk together flour and sugars.
Cut butter into flour mixture until it is well combined.
Spread mixture on your baking sheet and bake for 10 minutes, mixing half way through to ensure butter is well incorporated.
To prepare your frosting, add cream cheese, powdered sugar, cinnamon, and milk to the bowl of your stand mixer.
Whip for 5 minutes until cream cheese is smooth.
Load your piping bag with a 1 circle tip and set aside.
To prepare the triple berry jam add berries, sugar and water to a small pot and allow it to boil for roughly ten minutes, until the fruit is very soft.
Remove from heat and stir in corn starch, letting berries cool and thicken.
Once the berries are cool, place in a blender and puree.
Assembling the cookies, spoon 2 tablespoons of the berry jam on the top of each cookie.
Take your piping bag and frost your cookies starting in the middle and swirl in circles until you reach the outside of the cookie.
Take your prepared crumb mixture and sprinkle across the top of the cookies.