A/N: Written prior to the series finale and inspired by a photo found on tumblr.
The scent of sugar cookies and the squeals of their daughter's laughter rouse Rick from sleep, drag him into a pleasant wakefulness as he listens to the sounds of Kate and Ava downstairs, harmonizing to a song about winter wonderlands. Dancing as well, he sees once he dons a robe, descends the stairs of their Hamptons home to find his wife and his youngest daughter prancing around the kitchen.
"Look who's up," Kate chuckles, abandoning their daughter, who stands proud atop a stray chair from the dining area, happily singing off key to the music blaring from Kate's phone as she delicately places a snowflake shaped cookie cutter into the layer of dough spread out in front of her. "Morning sleepyhead."
Castle smirks into the kiss she presses to his mouth, tasting sugar on her lips.
"Your fault for keeping me up so late," he mumbles, squeezing her hip, encountering a patch of flour decorating the apron strung across her waist.
"I regret nothing," Kate throws back, skirting his hands and returning to Ava, murmuring her praise over the little girl's shoulder. "Good job, buttercup. These are going to look great."
"Daddy, are you going to help us make cookies for the party tonight? Momma said we're doing gingerbread next," Ava beams, her bright blue eyes shining in the morning light filtering through the clouds of winter outside.
"You're making my favorites next?" he gasps, receiving an eager nod in reply, the french braid Kate had twined her chestnut strands into whipping over her thin shoulders. "How can I resist?"
Castle jogs back to their room to change, rolling the sleeves of his sweater up to his elbows on the way back down, accepting the Christmas themed apron Kate hands him with a huff.
"Why do I get the Santa one?"
"Because you're jolly like Santa," Ava supplies for her mother.
"Is that a polite way of calling me fat?"
"Castle," Kate scolds, buries her laugh agains this cheek and pats his stomach for good measure. "Stop being a baby and knead some dough."
Kate places their sugar cookies in the oven to bake while Rick distributes the gingerbread dough between the three of them, spreads the assortment of cookie cutters out on the counter for Ava to choose from.
"Uncle Kevin is going to love these," Ava explains, pressing the signature gingerbread man shape into her splay of dough.
"Why's that?" Castle inquires, imprinting a reindeer shape into his. He's determined to create the entire pact that makes up Santa's sleigh pulling team.
"Because he loves gingerbread! And I'm going to make his entire family," she continues, retrieving a smaller size of the same cookie cutter shape. Rick had kept an entire collection of the cookie cutters from when Alexis was younger and they had picked them up from the storage space on the drive here, soaked them in the dishwasher overnight, and it had his chest swelling to see Ava recycling Alexis's old traditions. "Aunt Jenny, cousin Sarah, cousin Bella, and baby Bob."
Laughter bubbles from Kate's lips on Ava's opposite side. "Sweetie, Uncle Ryan and Aunt Jenny don't have a baby named Bob. He doesn't have a name yet because he's still in Aunt Jenny's tummy, remember?"
"I know, Mommy. But I have to call him something." Ava shakes her head in exasperation, a gesture he recognizes from Kate. He hopes it'll be a few years before their daughter picks up on the eye rolls, or even worse, 'the look'.
"I don't know if I'd vote for 'Bob', but she has a point," Castle concedes, startling when Kate reaches behind their daughter's back, delivers a pinch to his side. "Kate, you made me mess up Dasher."
"Mommy," Ava huffs, abandoning her gingerbread family to comfort her whining father. "Here, just stick his leg back on like this, Daddy. Don't give up on him."
Kate smothers her smile, her eyes melting into that soft gold as she watches Ava fix the broken leg of his reindeer with great care. His wife has always sworn that their daughter had been born with his heart, his love and compassion, but he would always argue that it was the opposite. The way Ava handled a broken cookie as if it was a wounded creature in need of tenderness was the way he had always witnessed Kate tend to the families of victims. Putting a piece of her heart into it every time.
"There." Ava smiles proudly at the reindeer with quite a large bulge in the back leg area. "All better."
Castle drops a kiss to the top of her head. "Thanks, sweetheart."
"I knew frosting was going to be a disaster between the two of you," Beckett sighs, but his grin only grows.
After all of the cookies had been baked and allowed the chance to cool, homemade frosting had been created, and while smears of vibrant greens, reds, and whites decorated Kate's fingers, he and Ava had the colors stained along their hands, their arms, and their cheeks. Which had mostly been his fault, but it had made the process of decorating cookies for the Christmas party even more fun and he knew that even as Kate shook her head at them, she had enjoyed every second.
Castle abandons Ava at the dining room table, the view of her finishing up with the last of the cookies clear from the kitchen, and comes up behind Kate at the sink.
"Beckett?"
She turns to glance over her shoulder and Rick quickly smears the white frosting down the tip of her nose. Kate jerks back from him, her eyes startled but her lips splitting into a sly smile as she reaches behind her, and oh no-
The burst of flour explodes from her fingertips, coats the side of his face and sticks in his hair, but he's already laughing, always delighted when she plays along, gives credence to the wonderful hints of childishness still buried within.
"I deserved that," he sighs.
Ava giggles from the table, red and green fingers rising to cover her mouth as she laughs at the two of them. Kate smothers her amusement against his lips, teasing her tongue along the seam, humming in a way that is far too arousing for the middle of the day with a kid in the room.
"Deserved that too," she murmurs, brushing her thumb through the layer of flour before stepping back, approaching their daughter with open arms.
"Let's go get you cleaned up so you can take a nap before the party."
"I don't want to nap," Ava sighs, wiping her hands on a paper towel.
"Why? Naps are the best," Castle says with a waggle of his brow for Kate.
"Just a little nap," Beckett placates their girl, narrowing her eyes at him before turning her attention to Ava, brushing the hairs that have fallen from her braid back from her face. "We've been up since early this morning, you don't want to be too tired when it's finally time for the party, do you?"
Ava mulls it over for a moment, so young but so wise, a little too wise for his liking. Alexis had been similar at this age, though, even worse, actually. His little girls always tended to grow up too fast.
"Okay Momma, are you still going to do my hair pretty?"
"Mhmm, and you'll get to wear that pretty red dress Gram picked out for you last week, remember?"
Ava wraps her arms around Kate's neck when she lifts her from the chair, spinning around to earn a peal of rich laughter before she carries her away from the mess of flour and frosting, towards the closest bathroom, chattering on about Ava's dress, about the upcoming festivities. The Christmas party would be fun, memorable and pleasant, just like it was every year that they hosted the holiday gathering in their Hamptons hideaway, but he thinks that the preparation, the sacred moments that come beforehand with his wife and his six year old, is where all of the true enjoyment lies.
"Oh and Castle?" Kate trots back down the hall, the sound of bathwater running in the distance. He catches her by the hips when she lifts on her toes, bracing her hands on his shoulders as she smudges another smile to his mouth. "Wait for me in the shower. I'll be needing a nap myself."