Cryptic Family Reunion: Bitter Asperities

Question

The answer to this puzzle is a list of ten thematically related words or proper names or phrases. Each of these is clued cryptically, and the theme is to be determined. Since the definition part of a cryptic clue would give away the theme, these cryptic clues use a family member (e.g., mom, sister) to stand in for the definition part of the clue. So for example, if the theme of the puzzle were chemical elements, "Sister picking at nit" would clue "tin". Note: the answers in this puzzle have non-English origins, but several have been assimilated into English. I hope you enjoy!

1. Bit of property appearing in map appeals at heart to Dad (9)
2. Niece is carrying Foucault novel after leaving school (9)
3. "Tribe seized seasoned lumber, cordage last," recalled Grandma (5,6)
4. Sisters swimming in tandem (8)
5. Sketchy Roman smuggles a fifth of scotch for Nonna (7)
6. Papa coring, then pureeing, quinces with love for Mama (9)
7. Uncle Eric wanders around Los Angeles (6)
8. Auntie to pitch Canadian provinces, while counting on unity after country discards borders (5,5)
9. Brother is in, too, invading Canadian outposts (8)
10. Sister's net income before taking second and third holidays (11)

Answer 1

These clues all conceal...

French desserts

As follows:

1. Bit of property appearing in map appeals at heart to Dad (9)
CHARLOTTE - LOT in CHART + (-app)E(-als);

2. Niece is carrying Foucault novel after leaving school (9)
CLAFOUTIS - FO(-u)CAULT* + IS ('u' is 'university');

3. "Tribe seized seasoned lumber, cordage last," recalled Grandma (5,6)
CRÈME BRÛLÉE - CREE containing LUMBER* + (-cordag)E;

4. Sisters swimming in tandem (8)
MENDIANT - INTANDEM*;

5. Sketchy Roman smuggles a fifth of scotch for Nonna (7)
MACARON - ROMAN* containing A and (-scot)C(h);

6. Papa coring, then pureeing, quinces with love for Mama (9)
DACQUOISE - DA ('Papa') + QUI(-n)CES* containing O ('love' in tennis);

7. Uncle Eric wanders around Los Angeles (6)
ÉCLAIR - ERIC* containing LA;

8. Auntie to pitch Canadian provinces, while counting on unity after country discards borders (5,5)
TARTE TATIN - TAR ('pitch') + TEN (number of Canadian provinces) containing (-s)TAT(-e) and I ('unity' = 1 in Mathematics, I in Roman numerals);

9. Brother is in, too, invading Canadian outposts (8)
CALISSON - IS within ALSO within C(-anadia)N;

10. Sister's net income before taking second and third holidays (11)
PROFITEROLE - PROFIT ('net income') + ERE ('before') containing (-h)OL(-idays).

As for the title:

ASPERITIES is an anagram of PATISSERIE (i.e. French desserts), so if you consider 'BITTER' as an anagram indicator the title is itself a cryptic clue!