Line a small rectangular baking tray or cake tin with baking parchment. If you don’t have any, tin foil also works.
Break or chop the milk chocolate into pieces and place them all in a large microwavable bowl. Pour over the condensed milk and mix together well.
Heat in the microwave for short bursts of around 30 seconds, stirring in between, until the chocolate has almost melted. Be careful not to overheat or burn the chocolate.
Once the chocolate is melted, beat well with a wooden spoon until it all comes together smoothly. Add the vanilla extract and mix in well.
Scatter half of the mini eggs over the base of the tray. Tip the fudge into the tin and spread around so it is in an even layer in the tin. Use a spatula to smooth the top down.
Scatter the remaining mini eggs on top of the fudge, then carefully push them all into the fudge, working quickly before it sets.
Pop the fudge into the fridge and leave to set for at least 2 hours or overnight. Once the fudge has set hard, take it and cut into pieces.