Preheat the oven to 350°F. Spray an 8-inch-by-8-inch pan with cooking spray, line with parchment paper, then spray the parchment paper with additional cooking spray.
In a medium-sized microwave-safe bowl, melt the chocolate with the coconut oil, stirring in 30-second increments until just melted. Set aside.
Toast the coconut in a dry skillet over low heat until golden brown and fragrant. Remove from heat.
In a medium-sized mixing bowl, combine the flour, brown sugar, vanilla, baking powder, and salt.
Add the eggs to the chocolate mixture and whisk to combine. Add the dry ingredients and ½ cup of the toasted coconut. Place ¼ cup Cadbury Mini Eggs in a plastic sandwich bag and hit with a rolling pin until broken into large chunks. Add to the batter and stir to combine.
Pour the batter into the prepared pan. Top with the remaining ½ cup toasted coconut, and lightly press the remaining ¼ cup whole Cadbury Mini Eggs over top. Bake until just firm, 20-25 minutes.