Prepare the Filling and Jam
1-Line a small cookie sheet with parchment: Line a small cookie sheet with parchment paper so the cheesecake centers lift away easily once frozen. In a small bowl, beat the cold cream cheese, sugar, and vanilla with an electric hand mixer on medium-high speed for about 2 minutes, until the mixture looks smooth, fluffy, and no longer grainy from the sugar.
2-Portion the filling into 20 mounds, about: Portion the filling into 20 mounds, about 2 teaspoons each, on the lined sheet. Gently press each one with the back of a spoon so you have thick little discs rather than rounded scoops, then freeze them until completely solid. For clean stuffing later, they should feel rock-hard, not just chilled.
3-Meanwhile, place the diced fresh strawberries and: Meanwhile, place the diced fresh strawberries and sugar in a medium pot over medium heat. Let the fruit bubble slowly for about 45 minutes, smashing some of it halfway through with a wooden spoon, then stirring more often near the end as it turns glossy and thick to keep it from catching on the bottom.
4-The jam is ready when it has: The jam is ready when it has reduced to a heaping 1/3 cup (80 ml) and looks more like a thick paste than a loose sauce. When you drag a spoon through it, the line should stay visible for a moment instead of flooding back right away, then the jam can go into the fridge to chill while you make the dough.

Mix the Dough
5-Preheat the oven to 350°F (175°C) and: Preheat the oven to 350°F (175°C) and line two baking sheets with parchment paper. In a medium bowl, whisk together the flour, baking powder, baking soda, and salt so the leavening is evenly distributed through the dough.
6-In a large bowl, beat the very: In a large bowl, beat the very softened butter and granulated sugar on high speed for about 2 minutes until pale, airy, and fluffy. Add the room temperature egg and vanilla, then mix on medium speed for 1 to 2 minutes more, until the mixture looks lighter in color and almost mousse-like.
7-Add the dry ingredients and mix on: Add the dry ingredients and mix on low speed only until no dry streaks remain. You want a soft dough that holds together well, without overworking it and making the final cookies heavy.

Swirl, Stuff, and Shape
8-Push about 3/4 of the dough to: Push about 3/4 of the dough to one side of the bowl and flatten the remaining 1/4 across the bottom. Spoon over 1/4 of the chilled jam, then repeat those layers in 1/4 increments until all the jam is added. Use a spatula to cut and fold the dough just a little, enough to create streaks and pockets of strawberry rather than turning the whole bowl pink.
9-Using a 2 tablespoon cookie scoop, divide: Using a 2 tablespoon cookie scoop, divide the dough into 20 portions. Flatten each piece in your hand, place a frozen cheesecake disc in the center, and pull the dough up and around it so the filling is fully enclosed, then shape it into a slightly flattened disc. At this stage, the dough should smell buttery and sweet, with that warm toasted note that makes these cookies feel like cheesecake crust in disguise.
10-Roll each dough disc in the extra: Roll each dough disc in the extra granulated sugar so the outside bakes up with a light crackle. Arrange 6 cookies at a time on the prepared baking sheet, leaving enough room for them to spread.

Bake and Cool
11-Bake for 11 to 12 minutes, until: Bake for 11 to 12 minutes, until the edges are set and the centers still look a little soft. Right after the tray comes out of the oven, use a large round cookie cutter to gently scoot each cookie into a more even circle if needed.
12-Let the cookies rest on the baking: Let the cookies rest on the baking sheet for 10 minutes before moving them to a wire rack. This cooling time is not optional, the cream cheese filling needs that time to settle and firm up so the centers taste creamy instead of runny.