Line a cookie sheet with parchment and set aside.
In a stainless steel bowl placed over a pot with simmering water, place the semi-sweet chocolate. Melt, stirring occasionally until melted.
Pour the chocolate on the parchment lined cookie sheet and with an offset spatula, spread the chocolate into a rectangle. Do not spread too thin.
Place the candy bar halves, M&Ms, and candy eyes on the surface of the melted chocolate. Press on the candy bars to help them sink into the chocolate. Do not submerge.
Set aside and leave in *room temperature until the chocolate solidifies. Break into pieces.
*Note: You can also place the cookie sheet in the freezer or fridge to help the chocolate solidify. Please note, if placing in freezer the chocolate will have some condensation once it comes to room temperature.