1. Preparing the Dough

1. Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
2. In a large bowl, cream together the softened butter and granulated sugar until light and fluffy.
3. Add the egg and vanilla extract, and mix until well combined.
4. In a separate bowl, whisk together the flour, baking powder, and salt. Gradually add the dry ingredients to the wet ingredients and mix until just incorporated.
5. Do not overwork the dough to ensure soft, tender cookies.

2. Dividing and Coloring the Dough

1. Split the dough into 4–6 equal portions (depending on how many colors you want to use).
2. Add a few drops of gel food coloring to each portion, kneading until the color is fully incorporated.
3. Flatten each portion of dough into a disc, wrap in plastic wrap, and chill for at least 30 minutes.

3. Creating the Swirl Effect

1. Roll out small portions of each colored dough.
2. Gently twist or fold the different colors together to create a marbled, swirl effect.
3. Shape the dough into balls and place them on the prepared baking sheet.
4. Using your thumb or the back of a spoon, press gently into the center of each ball to create a well.
5. Fill the well with jam halfway through baking for a glossy, beautiful finish.

4. Baking the Cookies

1. Bake for 10-12 minutes or until the edges are slightly golden.
2. Allow cookies to cool on a wire rack before serving.