Add butter, powdered sugar, salt, vanilla extract, and almond extract to the bowl of a large food processor. Process until smooth (about eight 1-second pulses). Add flour and pulse until mixture looks crumbly and chunky (about six 1-second pulses). Add sprinkles and quickly pulse several more times, until the sprinkles are just evenly incorporated.
Turn the dough out onto a large piece of wax paper and form the crumbles into a log that's about 14 inches long. Shape the log so that it has three flat sides, giving the ends a triangular shape (the log should look like a long triangular prism).
Wrap the triangular log with the wax paper. Take a wooden ruler (or another long, thin object) and press an indentation into one flat side of the log. Round the edges of that side to form a heart-shaped log. Place the wrapped cookie dough on a baking sheet and freeze for 15 minutes. Fine-tune the shape of the heart (if necessary) and freeze for 2 to 3 more hours or until solid.
Place rack in center position of oven. Preheat oven to 350°F. Line two baking sheets with parchment paper. Remove log of dough from the freezer. Allow the cookie dough to come to room temperature for 5 minutes or until just soft enough that it doesn't crack or crumble when sliced. Using a sharp knife, cut the log into slices that are approximately 3/8-inch thick. Arrange cookies an inch apart on the prepared baking sheets. Bake until cookies just barely turn a light golden color around the edges, between 12 and 15 minutes. Allow to cool on the baking sheets.