Cryptic crossword No 3,625

Across

1. Automatic heater - as a yank might put it, schvitz at last! That's between you and I (3)
2. I start to finish first of yummy Eccles cakes, after filling in the middle runs from end to end (4,6)
3. Heavens above, abandon God's son to suffer, therein securing the end to sacrilege (3,8,4)
4. Drawn in by topless gent covered in frosting (7)
5. A margin round a mean (7)
6. Disturbed routine in early human development site (2,5)
7. Hot wing on ice, in short, a producer of notes for the mouth? (9)
8. Evil triumphed over right and good (5)
9. Look closely after removing phial's lid - a class for flies! (7)
10. Spot to rest one night at first, then another (3)
11. Top-tier contents of tupperware (5)
12. Subtle observation derives pi on a generality, in part (9)
13. Put forth a stance about cross and down in a crossword being set side by side (10)

Down

1. Past lover maintained 1001 large fairy circles, and not just those closest to you? (8,6)
2. Ancient city with crumbling walls - in France, I start to riot; in Germany, I start to obey (7)
3. Furthermore 100 divides 1000, ending in none remaining (2,4)
4. Where some feathers take on their hue? (6)
5. That is, with our fifth egg broken, becoming a kind of twisted loop? (6,2,5)
6. Passage that returns to the atrium? (4,4)
7. Try again to hold back? (8)
8. One-time American consumes food regularly, producing outward mass movement (6)
9. Made food, having dependency on changing temperatures (6)
10. Sounds made by birds - primarily sparrows, quail, and Ugandan crestless hawks (7)
11. That lady's sheep take another turn; indication of déjà vu, perhaps? (4,2,2,5)
12. Loyal sorts to produce alloy - how so? (14)