Preheat the oven to 350 F. Line an 8X8 baking dish with parchment paper.
Melt the butter and chocolate in a microwave safe bowl for 1 minute and 30 seconds. Stir every 15 seconds to avoid burning.
Whisk in sugar, mix until well combined. Whisk in the eggs, one at a time, stir very well.
Stir in flour, mix slowly until fully combined.
Pour 3/4 of the batter in the baking dish, place 16 unwrapped snickers on top. Don't press them in.
Pour the remaining batter on top, using a spatula, spread the batter all over. Bake in the oven for 25-28 minutes until a toothpick inserted in the center comes our fairly clean.
Top with ganache and let it cool and firm, then cut into 16 pieces.