. Make and Freeze Cheesecake Filling Discs:

• Line a small cookie sheet or large plate with parchment paper.
• In a small bowl, add the cold cream cheese, 3 tbsp granulated sugar, and 1/2 tsp vanilla. Mix on medium-high speed with an electric mixer until fluffy and the sugar has dissolved, about 2 minutes.
• Scoop the cheesecake filling into 18 portions, using about 2 teaspoons for each portion, onto the parchment-lined sheet.
• Slightly flatten each scoop with the back of a spoon so they resemble thick discs rather than tall balls.
• Place the sheet in the freezer until the cheesecake discs are completely frozen solid (at least 1-2 hours).

2. Make and Chill Strawberry Jam:

• While the filling freezes, make the jam. Add the finely diced fresh strawberries and 1/4 cup granulated sugar to a medium pot over medium heat.
• Cook, stirring occasionally, until the strawberries break down and the mixture comes to a boil. Reduce heat slightly to maintain a steady simmer.
• Continue simmering for about 45 minutes total. Stir frequently, especially towards the end, and mash the berries with a wooden spoon about halfway through. The jam needs to reduce significantly and become very thick (should yield a heaping 1/3 cup / 80 ml). It will thicken more as it cools.
• Test for thickness: If you can draw a line through the jam on the back of a cold spoon and it holds briefly, it’s likely ready.
• Remove the jam from the heat. Transfer it to a small bowl, cover with plastic wrap (press onto surface), and place it in the fridge to chill completely while you make the cookie dough.

3. Make the Cookie Dough:

• In a medium bowl, whisk together the 2 3/4 cups all-purpose flour, baking powder, baking soda, and salt. Set aside.
• In a large bowl using an electric hand mixer (or stand mixer with paddle), cream the very softened butter and 1 cup granulated sugar together on high speed until light and fluffy, about 2 minutes.
• Add the room temperature egg and 2 tsp vanilla extract. Mix on medium speed until pale in color and very fluffy, about 1-2 minutes more. Scrape down the bowl.
• Add the dry ingredients to the wet ingredients. Mix on low speed just until combined. Do not overmix.

4. Fold in Strawberry Jam:

• Push about three-quarters of the finished cookie dough to the side of the large mixing bowl.
• Flatten out the remaining one-quarter of the dough along the bottom of the bowl. Spoon about one-quarter of the chilled strawberry jam onto that section of dough.
• Take another quarter of the dough from the side, place it over the jam/dough layer. Spoon another quarter of the jam on top. Repeat this layering twice more (Dough-Jam-Dough-Jam-Dough-Jam-Dough). You are essentially layering the jam between sections of dough in the bowl.
• Using a rubber spatula, gently “cut” through the layers in quarters and fold each section over just a few times until the jam is slightly swirled in, leaving visible pockets and streaks. Do not mix the jam in completely.

5. Assemble the Stuffed Cookies:

• Prepare your oven and baking sheets: Preheat the oven to 350°F (175°C). Line two baking sheets with parchment paper.  
• Place the 1/4 cup granulated sugar for rolling in a small shallow bowl.
• Remove the cheesecake discs from the freezer. Keep them frozen until ready to stuff each cookie.
• Scoop the jam-swirled dough into 18 portions using a 2-tablespoon cookie scoop.
• Take one dough portion, slightly flatten it in your palm. Place one frozen cheesecake disc in the center.
• Carefully enclose the cheesecake disc completely with the cookie dough, ensuring there are no gaps or cracks where the filling could leak out. Seal the edges well.
• Shape the stuffed dough into a slightly flattened disc (rather than a tall ball, as noted this helps prevent excessive spreading upwards instead of outwards).
• Roll the entire stuffed cookie dough disc gently in the granulated sugar until coated.
• Place the sugar-coated cookie dough onto a prepared baking sheet. Repeat with remaining dough and frozen cheesecake discs, placing about 6 cookies per sheet, well-spaced. Work relatively quickly to keep the cheesecake frozen. (Keep unstuffed cheesecake discs in the freezer between batches).

6. Bake the Cookies:

• Bake one tray at a time for 11-12 minutes, or until the edges are lightly golden and the tops look set.
• Optional Shaping: As soon as the cookies come out of the oven, while still hot and soft, you can use a large circular cookie cutter (larger than the cookie) to gently “scoot” around the edges of each cookie, nudging it into a more perfect circle.

7. Cool and Serve:

• Let the cookies cool on the baking sheet for about 10 minutes, as they will be very soft right out of the oven.
• Carefully transfer the baked cookies to a wire cooling rack to cool completely.
• Serve once cooled. Store leftovers in an airtight container.