Who says family recipes have to stay the same forever? In this tweaked family recipe, cookies are topped with a crumbly streusel topping and then drizzled with caramel. These cookies are not one you will make once and never again because everyone will want more. Cookies came about during an experiment on making cakes. Since then people have been customizing cookies to their liking by adding various flavors and toppings.
Place the brown sugar, cream, butter, vinegar, salt, cinnamon, and diced apple into a medium saucepan over medium-high heat. Bring the mixture to a rolling boil stirring constantly. Decrease the heat to low and then continue to cook for 5 minutes, stirring constantly, or until thickened.
Remove the filling from the heat and whisk in the vanilla.
Set aside to cool.
In a large bowl, cream the butter and sugar on medium speed for 2 minutes.
Add the vanilla and mix for 30 seconds on medium speed.
On low speed, slowly add the flour a 1/2-cup at a time; mix until just incorporated.
Bring the dough together with your hands into a ball, place it back into the mixing bowl, cover the bowl with plastic wrap, and then refrigerate the dough for 30 minutes.
Preheat oven to 350 degrees.
Shape the dough into 1-inch balls and then place them at least an inch apart on a Silpat or parchment paper lined baking sheet.
Using your thumb or the back of a spoon, press an indentation into the center of each ball.
Fill the indentation of each thumbprint cookie with some of the cookie filling.
Add the brown sugar, oats, flour, and salt to a small bowl. Stir together with the tines of a fork to combine.
Add the melted butter and stir again until well combined.
Sprinkle the topping over the filled thumbprint cookies and bake for 12 minutes.
Allow the cookies to rest for 3 minutes before removing them to a cooling rack.
Drizzle the cookies with any remaining cookie filling.