Mix room temperature unsalted butter and sugar in the bowl of a stand mixer using the paddle attachment, or in a large bowl using a hand mixer, on medium speed, until fluffy.
Gradually add eggs and vanilla, beating until well combined.
Sift flour, baking soda, and salt into the bowl. Mix sifted flour mixture into butter mixture on low speed until a soft dough is formed.
Wrap dough tightly in plastic wrap and chill for 2 hours or up to overnight.
When you are ready to bake, preheat oven to 350 F. Line cookie sheets with parchment paper or a silicone baking mat.
Stir together cinnamon sugar topping in a small bowl. Use a 2 tsp cookie scoop to shape dough into small balls. Roll cookie dough balls in the cinnamon sugar mixture, then place on prepared cookie sheet, 3 inches apart. Use the flat bottom of a cup or measuring cup to flatten each dough ball to 1/4 inch thickness. Dip again in cinnamon sugar mixture, then add almond slices to form sand dollar's star-shaped pattern.
Bake cookies 10-12 minutes until lightly browned around the edges. Cool 5 minutes in pan, then transfer cookies to a wire rack to fully cool.
Notes
These cookies keep well in an airtight container for several days.