In a medium bowl, simply whisk together your flour, baking soda, and baking powder. Set this dry mix aside for a moment.
In a large mixing bowl, beat the softened butter and granulated sugar together until they become light and wonderfully fluffy.
Mix in the egg, vanilla extract, almond extract, and sour cream. Continue beating until everything is smoothly incorporated.
Gradually add your dry flour mixture to the wet ingredients. Mix on low speed until just combined – try not to overmix! The dough will be a bit sticky, which is perfectly normal. Remember to scrape down the sides of your bowl as needed.
Gently form the sticky dough into a flat disc, about 1 inch thick, and wrap it tightly in plastic wrap. Place it in the refrigerator to chill for at least two hours; this crucial step makes it easier to roll.
Once your dough is perfectly chilled and you're ready to bake, preheat your oven to 425°F (220°C).
Line a baking sheet with a silicone mat or parchment paper to ensure your cookies don't stick.
Lightly flour your clean work surface. Roll out the chilled dough to about 1/4 inch thickness. Use a 3-inch cookie cutter (heart shapes are absolutely perfect for Valentine's Day!) to cut out your cookies. Carefully transfer them to your prepared baking sheet.
Bake for just 6-7 minutes. You'll know they're done when the edges are lightly golden and the cookies look nicely set.
Transfer the warm cookies to a wire rack to cool down entirely. They must be completely cool before you even think about frosting them!
While the cookies are cooling, beat the softened butter and vanilla extract together in a clean bowl until smooth and creamy.
Slowly add the powdered sugar, mixing until it's fully incorporated into the butter mixture.
Add the milk, one tablespoon at a time, beating until your frosting is delightfully light and fluffy. If you wish, mix in a few drops of pink or red food coloring to make it extra festive for Valentine's Day!
Once the cookies are fully cooled, spread a generous layer of your delicious, fluffy frosting on top. Finish with your favorite Valentine's sprinkles, if you desire, for an extra touch of love!