Spoon the Oreo's into the bottom of the hearts - spread them out to cover the entire bottom
Melt the white chocolate - I melted mine in the microwave, but be careful not to over cook it!
Spoon the chocolate into the hearts
Immediately sprinkle the sprinkles on top of the chocolate (you may want to gently push them down with your finger if the chocolate is already starting to firm up
Place the tray into the refrigerator until set
Notes
I found my heart silicon mold here: https://amzn.to/2mvtNn3(affiliate link)