“Thumbprint cookies” have sometimes been called “Swedish cookies” (“hallongrotta” or plural “hallongrottor”). The butter cookies are indented with a thumbprint in the center, and these thumbprints are filled with jam, jelly or another filling.
 
Recipes for “Thumbprint Cookies” were printed in the Pittsburgh (PA) Press on December 2, 1947, and the Boston (MA) Daily Globe on March 21, 1949. A recipe for “Swedish Thumbprint Cookies” was printed in the Ottawa (ON) Citizen on October 29, 1956.
   
A recipe for “Swedish Tea Cookies” printed in the South Bend (IN) Tribune on February 19, 1947, is the same as for “thumbprint cookies.”
   
   
Wikipedia: Hallongrotta
Hallongrotta (plural: hallongrottor) is the name of a common Swedish pastry (cookie). The name means “Raspberry cave” in Swedish. In the United States they are known as thumbprint cookies. It is an easily baked molded cookie, flavored with vanilla. The cookies are usually filled with raspberry jam.
   
19 February 1947, South Bend (IN) Tribune, “Recipes for Your Scrapbook” by Mrs. Harvey F. Rostiser, pg. 12, col. 5:
Swedish Tea Cookies.
One-half cup butter or substitute.
One-fourth cup brown sugar.
Yolk of one egg, slightly beaten.
One cup flour.
Mix ingredients and roll into little balls. Dip in egg white, slightly beaten and roll in ground nuts. Place on greased pan and roll in the center. Bake five minutes in a slow oven. Remove and press in the center again. Bake 10 minutes more. Fill center with red jelly or jam.
   
2 December 1947, Pittsburgh (PA) Press, “Holiday Guests Always Receptive to Homemade Cookies” by Jospehine Gibson, pg. 25, col. 3:
Thumbprint Cookies
3/4 cup finely chopped nuts.
1/4 cup soft shortening.
1/4 cup soft butter.
1/4 cup brown sugar (packed in cup).
1 egg yolk.
1/2 teaspoon vanilla.
1 cup sifted all-purpose flour.
1/4 teaspoon salt.
1 egg white.
Mix shortening, butter, brown sugar, egg yolk and vanilla together thoroughly. Sift together the flour and salt and stir into butter mixture. Roll in balls, size of a small walnut. Beat egg white slightly with fork; dip balls in egg white. Roll in the finely chopped nuts. Place about 1 inch apart on greased baking sheet. Bake 5 minutes in quick moderate oven of 375 degrees F. Remove from oven. Immediately press thumb gently in top of each cooky. Return to oven and continue baking about 8 minutes longer. Makes about 2 dozen cookies.
Note—to add an extra decorative effect, when cookies are cool, place a bit of chopped candied fruit, bright jelly, or flavored confectioners’ sugar icing in indentations. icing may be tinted, if desired.
   
12 November 1948, New Castle (PA) News, pg. 2, col. 1 ad:
Swedish Tea Cookies ... doz. 35c
with date filling. Very nice for your parties and luncheons.
(Danish Pastry Shop, 26 North Mill Street.—ed.)
 
21 March 1949, Boston (MA) Daily Globe, “Globe Family Recipes,” pg. 6, col. 1:
Thumbprint Cookies.
One-half cup shortening, 1/4 cup brown sugar, 1 egg yoke, 1/2 teaspoon vanilla, 1 cup sifted flour, one-fourth teaspoon sifted salt. Mix together shortening sugar, and yoke and vanilla. Sift together flour and salt and mix well. Roll into 1-inch balls. Dip in slightly beaten egg whites and roll in finely chopped nuts. Place about 1 inch apart on ungreased baking sheet. Bake 5 minutes and remove from oven. Quickly press thumb gently on top of each cookies. Return to oven and bake 8 minutes longer and cool. Place in thumbprints a bit of chopped candied fruit or jelly. Bake in a 375 degree oven.
Cakes and Cookie.
     
21 December 1950, Vancouver (BC) Daily Province, “Red Cherries Brighten Kris Kringles,” pg. 39, col. 1:
Kris Kringles are a Christmas time version of the old favorite Thumbprint or Swedish cookies.
 
29 October 1956, Ottawa (ON) Citizen, “Mary Moore’s Meals: Fine Christmas Cookies For Guests, For Gifts,” pg. 26, col. 4:
Swedish Thumbprint Cookies
One half cup butter, 1/4 cup sugar, 1 egg yolk, slightly beaten, 1 cup flour, 1 egg white unbeaten, 3/4 cup fine chopped nuts. Cream butter well, add sugar creaming well, add egg yolk, beat well. Add flour. Form into 3/4 inch balls between palms, roll in the white of egg and then in the nuts and place on greased cookie sheet. Press almost flat with a glass. Bake 3 minutes at 300 deg. Fah. Remove and make a depression in centre and then bake 15 mins. Fill depression with tart jam or jelly. 
 
Google Groups: rec.food.recipes
Swedish Thumbprint Cookies
Elaine Ackerman
1/15/04
Swedish Thumbprint Cookies
These very pretty (and easy) cookies are some that I’ve enjoyed since I was very small. I grew up in a Scandinavian neighborhood, and our next door neighbor always gifted us with a plate of these cookies at Christmas time. You can vary their look by using a variety of different jams and nuts. The jam centers give a jewel-like appearance.
 
Makes about 4 dozen (or less, depending on size)
 
1/2 pound (2 sticks) unsalted butter
1/2 cup granulated cane sugar
1 extra large egg yolk
1 teaspoon pure vanilla extract
1 tablespoon light cream
2 1/4 cups unbleached flour
Pinch of Rumford’s baking powder
1/2 cup finely chopped walnuts (or choose pecans or pistachios)
1 extra large egg white
 
Google Books
Fire and Ice:
Classic Nordic Cooking
By Darra Goldstein
New York, NY: Ten Speed Press
2015
Pg. ?:
Hallongrottor
RASPEERRY GROTTOES
THESE SMALL, RASPBERRY-FILLED cakes are conceptually similar to American thumb-print cookies, but far more buttery and delectable.
 
YouTube
Thumbprint Cookies (Classic Version) - Joyofbaking.com
Joy of Baking
Published on Sep 20, 2011
Recipe here: http://www.joyofbaking.com/Thumbprint... Stephanie Jaworski of Joyofbaking.com demonstrates how to make Thumbprint Cookies. Thumbprint Cookies are a very popular holiday cookie. They are made with a shortbread-like dough that is formed into balls and then rolled in either finely chopped nuts or dried coconut. The name ‘thumbprint’ comes from the fact you use your “thumb” to make an indentation into each ball of dough and then fill it with jam.
       
Twitter
famousacts
@famousacts1
Vegan Thumbprint Cookies … tasty, fun and easy to prepare! Clickable recipe li… https://www.famousacts.com/vegan-thumbprint-cookies-tasty-fun-and-easy-to-prepare-clickable-recipe-li/ …
3:34 AM - 30 Jan 2019
 
Twitter
Whole Earth Foods
@wholeearthfoods
🥜 🍪 🐢These Peanut Butter Turtle Thumbprint Cookies look a-maz-ing!
Full recipe 👉 https://www.thereciperebel.com/peanut-butter-turtle-thumbprint-cookies/ …
#ItsNotJustForToast
#PeanutButterLovers #PeanutButter
#WholeEarthFoods
5:12 AM - 30 Jan 2019
 
Twitter
Eat Keto With Me
@EatKetoWithMe
Raspberry thumbprint cookies are easy gluten free and low carb cookies with an almond flour base and a fruity raspberry jam filling. They are perfect for low carb, Keto and sugar free diets. #raspberry #cookies #sugarfree #lowcarb http://bit.ly/2To9dCM
12:25 AM - 30 Jan 2019