1. Preheat the oven at 170℃
2. Take a medium mixing bowl, add the softened butter and beat with a hand held mixer at medium speed until fluffy.
3. Add the icing sugar and continue to beat until well combined.
4. Add the milk, the egg and the vanilla extract into the butter mixture. Continue to beat for about 1 to 2 minutes. Don’t worry if the mixture appears to curdle at this stage.
5. Place a sift on top of the mixing bowl, sift in the flour, sweet potato powder and sea salt. Use a spatula to mix in the dry ingredients first to avoid powder flying up to your face. Then continue to beat it with a hand held mixer until the mixture turns into a dough.
6. Once it turns into a dough, stop the mixer immediately. Use the spatula to scrape down the sides and the bottom of the bowl to make sure everything is well mixed.
7. Prepare two sheets of parchment paper. Place one sheet on the work surface and scoop half of the dough onto it. Sandwich it with the other sheet of parchment paper.
8. Roll out the dough to a thickness of 4 mm, using a rolling pin.
9. Chill the dough in the refrigerator for 30 minutes or until it is firm.
10. Repeat the same process for the second portion of the dough.
11. Once the dough is firm, take it out from the refrigerator and place it on a flat surface. Cut out the cookie circles for the cookie bottoms, using a cookie cutter. Place each cookie circles an inch apart on a lined baking tray (but see step 12, you may need to cut out the heart shapes first before placing them on the tray).
12. To cut out cookie tops with the heart-shaped in the middle, you can either use a heart-shaped cutter to cut the shapes out of the cookie bottoms or, if you have the specialist tool that allows you to change cutters, insert the heat-shaped and continue to cut directly from the dough. Make sure you cut an equal amount of tops and bottoms! Place all cookies onto a lined baking pan, an inch apart.
13. Bake the cookie bottoms for about 13 to 15 minutes and the heart-shaped tops for about 10 to 12 minutes. Or in both cases until the edges begin to turn golden brown. Keep a close eye on them as they bake.
14. Once baked, leave the cookies on the baking pan for about 5 minutes before transferring them onto a wire rack to cool down completely.
15. Dust the heart-shaped cookies with icing sugar.

Make the white chocolate ganache

1. Chop the white chocolate into small pieces for easy melting.
2. Place the cream and the chopped white chocolate into a medium mixing bowl.
3. Place the bowl in the microwave on a cook setting for 30 seconds each time to melt. Mine took about 3 times. Stir it well between each time, using a silicone spatula.
4. Place the white chocolate mixture in the refrigerator to chill for about 10 to 15 minutes.
5. Use a hand held mixer to beat the mix until it turns lighter in colour and fluffier in texture.
6. Add in a few drops of electric purple gel food colouring to dye it into your desired shade.
7. Cut a hole at the end of the piping bag and place the piping nozzle into it. Place the bag into a tall glass for easy loading the purple chocolate ganache. Flip the top down and start scooping the ganache into the piping bag. Secure with a rubber band.

Assemble the cookies

1. Pipe the chocolate ganache on the non-dusted cookie circles. Place the heart-shaped ones on top, taking care not to crack them with too much downward pressure.
2. Enjoy these delicious treats with your loved one! Happy Valentine’s Day! They also taste great on the other 364 days each year. Share the love.