Fill a regular sized 12 cup muffin tin with paper liners. Set aside.
In the bowl of a food processor, pulse the flour, oats, sugars, baking powder and salt until blended. Add the butter and vanilla. Pulse until the mixture becomes a crumbly dough. Scrape down the sides of the bowl if needed to help it combine. Some of it will seem dry - that's okay.
Transfer the cookie dough to a large bowl and stir to combine. The dry crumbs in the bottom will be used for the streusel so no worries if it all won't stick together.
Scoop out 1 rounded tbsp. Drop balls into one of the mini tin wells. Using your fingers lightly press the dough into the bottom of the muffin tin making sure it is level. Repeat until the muffin tin is full.
Dollop one small amount of preserves into the center of the cookie base in the muffin tin. Using a small spoon scatter crumbled dough around the outside edges of the cookie surrounding the preserves. Press very lightly if needed to hold it together.
Bake for 13-17 minutes, rotating the pan halfway through baking until the preserves are bubbling and the cookie is lightly browned on the edges. Do not over-bake! Allow the cookies to cool in the muffin tin for at least 5 minutes, Remove from pan and carefully remove paper from cookie. If it starts to crumble, let it cool a little longer. Once cooled, store at room temperature in an airtight container. Cookies will keep for up to 5 days.