• Preheat the oven at 170℃
• Take a medium mixing bowl, add the softened butter and beat with a hand held mixer at medium speed until fluffy.
• Add the icing sugar and continue to beat until well combined.
• 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.
• 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.
• 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.
• 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.
• Roll out the dough to a thickness of 4 mm, using a rolling pin.
• Chill the dough in the refrigerator for 30 minutes or until it is firm.
• Repeat the same process for the second portion of the dough.
• 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).
• 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.
• 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.
• Once baked, leave the cookies on the baking pan for about 5 minutes before transferring them onto a wire rack to cool down completely.
• Dust the heart-shaped cookies with icing sugar.

Make the white chocolate ganache

• Chop the white chocolate into small pieces for easy melting.
• Place the cream and the chopped white chocolate into a medium mixing bowl.
• 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.
• Place the white chocolate mixture in the refrigerator to chill for about 10 to 15 minutes.
• Use a hand held mixer to beat the mix until it turns lighter in colour and fluffier in texture.
• Add in a few drops of electric purple gel food colouring to dye it into your desired shade.
• 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

• 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.
• 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.