Pour the tempered chocolate into a silicone swirl cake mold and swirl the mold around until the inside is completely coated with chocolate. Refrigerate the cake mold and let the chocolate set.
Separate the eggs and beat the egg yolks and ¼ cup of sugar with a hand mixer until fluffy. Also beat the egg whites and ¼ cup of sugar with a hand mixer until fluffy. Fold the mascarpone into the egg yolk mixture and then carefully fold in the egg white mixture.
Spread ¾ of the mascarpone cream over the hard chocolate shell in the cake mold and smooth out the top. Break the Danish butter cookies in half, place them on top of the mascarpone cream, and brush cold coffee over the cookies. Spoon the blueberry pie filling over the cookies.
Spread the rest of the mascarpone cream over the blueberry pie filling and refrigerate the cake mold for at least 6 hours, or preferably overnight. Flip the chilled cake mold over onto a serving platter and carefully remove the cake mold before serving.