1. Start by creaming together the shortening and granulated sugar in a medium-sized bowl. Beat them together until the mixture is light and fluffy. This will take about 2 to 3 minutes, and it’s crucial for creating a tender cookie base.
2. Add the eggs, milk, and vanilla extract to the creamed mixture. Mix until everything is well incorporated. You should have a smooth, creamy mixture that’s slightly thick.
3. In a separate large bowl, combine the dry ingredients: all-purpose flour, baking powder, and salt. Whisk them together to ensure there are no lumps.
4. Slowly mix the dry ingredients into the wet mixture. Stir gently until you form a large dough ball. Don’t overmix; you want to keep the mixture tender.
5. Once your dough is formed, wrap it in plastic wrap and refrigerate for at least 30 minutes, or overnight if you can. Chilling the dough helps it maintain its shape while baking.
6. When you’re ready to bake, preheat your oven to 350 degrees F and grease a standard-sized muffin tin thoroughly. This step is key to ensuring your cookie cups come out easily.
7. Roll the chilled dough into 1-inch balls. Pat them gently in your hand to flatten slightly. You want to create little discs that will fit into your muffin tin.
8. Place each dough disc into the greased muffin tin. Press the dough down flat and up along the sides, creating a cup shape. Aim for a thickness of at least 1/4 inch.
9. Continue this process with the remaining dough. Once all the cups are formed, bake them in the oven for about 8 to 10 minutes. Watch carefully, as baking times can vary.
10. If you find that your cups have lost their shape, remove them from the oven at 8 minutes. Use a small spoon to gently press down the centers and reshape the sides, then return to the oven for an additional 3 minutes.
11. Once baked, remove the cookie cups from the oven and let them cool for a few minutes. Use a knife to trace along the edges to loosen them, then carefully remove them onto a wire rack to cool completely.
12. While the cookie cups are cooling, prepare the lemon filling. In a large saucepan, combine granulated sugar and cornstarch. Whisk in milk and fresh lemon juice until smooth.
13. Cook over medium heat, stirring constantly, until the mixture thickens and bubbles. This usually takes about 5 to 7 minutes.
14. Once bubbling, reduce the heat to low and cook for another 2 minutes. This allows the flavors to meld beautifully.
15. To temper the egg yolks, add a spoonful of the hot mixture into the yolks and stir. Repeat this process two or three times to gently raise the temperature of the yolks without cooking them.
16. Pour the tempered yolk mixture back into the saucepan, stirring continuously. Bring the mixture to a gentle boil and cook for an additional 2 minutes, then remove from heat.
17. Add in the butter and lemon zest, stirring until the butter has melted and is fully incorporated.
18. Let the filling cool before stirring in the Greek yogurt until smooth.
19. Spoon a heaping tablespoon of the lemon filling into each cooled cookie cup. It’s tempting to overfill, but a spoonful will do nicely!
20. Refrigerate the filled cookie cups for at least 30 minutes before topping them with fresh fruit. This helps the filling set up perfectly.
