Across
Accountant tucking into reddish-purple almondy biscuit (8)
University invested in Lamb's complete works? Praise the Lord! (8)
I haven't cracked this one yet — but Times for the Times have:
U (university) contained by [invested in] ALL ELIA (Lamb’s complete works). Charles Lamb (1775 – 1834) was an English essayist and poet who wrote under the pen-name Elia.
Danish prince losing head about king's band (6)
I haven't cracked this one yet — but Times for the Times have:
{h}AMLET (Danish prince) [losing head] containing [about] R (king)
Crook in US city with last of beer in mug (10)
I haven't cracked this one yet — but Times for the Times have:
LA (US city), W (with), then {bee}R [last of…] contained by [in] BEAKER (mug)
One in opposition essential to Victorian times (4)
Reform apt in a lone Italian citizen (10)
Frenzied French worker perhaps in charge (7)
Acolyte unknown where food is dished out (7)
I haven't cracked this one yet — but Times for the Times have:
SERVER (acolyte), Y (unknown)
Boss dropping a pipe by new Bavarian wear (10)
I haven't cracked this one yet — but Times for the Times have:
LE{a}DER (boss) [dropping a], HOSE (pipe), N (new). We seem to have heard of these quite a lot recently. Must be something about the time of year.
Sticky substance lying around a Pacific island (4)
I haven't cracked this one yet — but Times for the Times have:
GUM (sticky substance) containing [lying around] A. It was handy that the island came up in wordplay in a recent Jumbo as I didn’t know it then.
Very quiet in middle of supper? (10)
I haven't cracked this one yet — but Times for the Times have:
Hidden [in middle of] {su}PP{er}. PP (or rather pp) is the standard abbreviation for this answer.
One practised a form of civil disobedience in compound (6)
Midday issue with denial for one retracted (8)
Name of bank used by the Spanish? Nonsense (8)
Down
Supplier of oxygen required at first for passenger plane (8)
I haven't cracked this one yet — but Times for the Times have:
AIRLINE (supplier of oxygen), R{equired} [at first]
Loyalty shown by chap caught in hold (10)
I haven't cracked this one yet — but Times for the Times have:
IAN (chap) + C (caught) contained by in ALLEGE (hold). I’m struggling to think of a context in which hold = ALLEGE. They’re in the Chambers Crossword Dictionary and in Collins as synonyms, but no examples of usage are given. [Edit: Thanks to Galspray for the example suggested below which I think works].
Exotic blooming country is hot (10)
At sea warn prince, finding toothed marine mammal (7)
Confuse hanger-on holding line (4)
Crossing Welsh river, came across old firearm (6)
Barefaced attorney finally upholding women's contract (8)
I haven't cracked this one yet — but Times for the Times have:
W (women’s), ARRANT (barefaced), {attorne}Y [finally]
In Congo, age dreadfully, like some greyhounds? (5-5)
Enliven Spanish port cutting current charge (10)
Half-heartedly excite popular old Asian islander (8)
I haven't cracked this one yet — but Times for the Times have:
FIL{l}IP (excite – urge, stimulate), [half-heartedly], IN (popular – current), O (old)
Responsive to stimulus concerning voice (8)
Aimed to resolve despair (7)
Teacher digesting trashy paper, a formidable type (6)
Cricketer's blunder (4)
Type letters or click words in the clue