In a bowl, whisk together flour, baking powder, confectioners sugar, salt, and cinnamon.
In another bowl, beat butter and sugar until light and fluffy. Mix in vanilla and egg.
Gently fold the dry ingredients into the butter mixture until just combined.
Divide dough in half, shape into discs, wrap, and refrigerate for at least 2 hours.
Preheat oven to 375°F (190°C). Roll chilled dough between parchment to ⅛-inch thickness.
Cut out cookies, making half solid and half with center cutouts. Chill cut cookies for 5 minutes.
Bake for 8–10 minutes, until edges are lightly golden. Cool briefly, then transfer to a rack.
Warm strawberry jam over low heat for about 7 minutes, stirring occasionally.
Spread jam onto solid cookies. Top with cutout cookies and press gently.
Dust lightly with confectioners sugar before serving.
