Hey, there isn’t a Raise Dead spell for Lamentations of the Flame Princess. There’s no reason there shouldn’t be but it’s still got to have that special something that makes it Flame Princess worthy. So here’s my modest attempt.
First, here’s a couple of my thoughts this spell. Death is natural (cause of death might not be). Death is one of the laws of the universe and everything dies eventually. Cheating death unbalances the universe and is a Chaotic act. So in this case the spell is a Magic-User spell rather than a Cleric spell. Also, returning the dead to live should be time consuming, expensive, and dangerous. So here you go.

Raise Dead
Magic-User Level 5
Duration: Permanent
Range: Touch

The Magic-user attempts to defy the laws of the universe and return a fallen being to life.
Fist, the dead body must be as whole as possible. Missing limbs and organs are not replaced. The caster must acquire rare oils and spell components with a value of 1,000 SP per Level/Hit Die of the target. Additionally, the caster must perform a long and precise ritual lasting 1 hour per Level/Hit Die of the target. As part of this ritual, the caster must attempt to bring some sort of balance to the universe by sacrificing a number of sentient beings of the same race as the target. The total Levels/Hit Dice of the sacrifices must at least equal the Level/Hit Dice of the target.
Once the ritual is completed, both the caster and the target attempt a Saving Throw versus Magic. If both succeed then the spell was successful and the target returns to life with 1 Hit Point.
If either of them fail so does the spell. Roll 1d20 on the following chart. If both fail then roll 1d10+10 on the following chart. The spell may not be attempted again.
A cleric will not witness or partake in this ritual. Also, a cleric cannot be the target of the spell.

1: The body is consumed in a divine fire leaving nothing but ash.
2: The body shows all the signs of life but no soul has entered it. It will expire from dehydration in a matter of days.
3: The target’s soul reenters the body but the transition was too much. The target has total amnesia and is now a Level-0 character.
4: The target’s body explodes with necromatic energy causing Level/Hit Dice D6 of damage to every thing in a 30 foot radius. Save versus Breath Weapon for half damage.
5: The caster accidentally summons the spirit of wrong person. This can be any dead person from history as determined by the GM. But chances are that it will be some historically insignificant person.
6: The soul of the target ends up in the nearest animal no smaller than a rat.
7: The caster’s and the target’s souls switch bodies.
8: The target’s soul ends up in a random item. That item is now magical and has powers based on the class and level of the target and GM’s discretion.
9: It looks like the spell worked. The target will live for 1d100 days (GM rolls secretly) then target drops dead, his corpse rotting away to nothing in seconds.
10: The target’s soul does not enter his body but is turned into a vengeful ghost which attacks and haunts the party.
11: The caster accidentally summons some otherworldly entity that now possesses the body of the target.
12: The ritual fails but summons forth 2d6 angry ghosts which immediately attack any present.
13: The target’s body explodes in a shower of flesh eating maggots. Save versus Breath Weapon or take 1d6 damage each round until the character makes a successful Save versus Disease.
14: The spell mostly fails. The target’s soul reanimates the body but as a form of free-willed, intelligent undead.
15: The caster loses a number of levels equal to the Level/Hit Die of the target. If this drains the caster to 0-Level then the caster is killed.
16: The spell weakens the veil between the mortal world and the Underworld. The area will be haunted by ghosts and become prime habitat for undead creatures.
17: The spell loosens the connection between body and soul. Each being within a 30 foot radius must Save versus Magic. Those who fail their Saving Throws have their souls switched to another random body. If only one character fails the saving throw then his soul is ripped from this body.
18: An Angel of Divine Retribution descends on the area killing every sentient being in a radius of the target’s Level/Hit Die x miles. Save versus Death or die.
19: Every dead creature in an area in radius equal to the target’s Level/Hit Die x 100 miles is re-animated as zombie.
20: An area in radius equal to the target’s Level/Hit Die x 100 miles is drained of life. All creatures 4 HD or less are instantly killed. Those with more than 4 HD are allowed a Saving throw versus Death or die. This effect lasts in the area for one year. For one 100 years, no plant life will grow in this area and animals will avoid it.