diff --git a/esphome/components/api/api_frame_helper.cpp b/esphome/components/api/api_frame_helper.cpp
index c18bba0bee8..88bbbe697fb 100644
--- a/esphome/components/api/api_frame_helper.cpp
+++ b/esphome/components/api/api_frame_helper.cpp
@@ -112,13 +112,7 @@ APIError APIFrameHelper::drain_overflow_and_handle_errors_() {
   return APIError::OK;
 }
 
-// Single-buffer slow path: wraps data in iovec and delegates to the iovec slow path.
-APIError APIFrameHelper::write_raw_slow_(const void *data, uint16_t len, ssize_t sent) {
-  struct iovec iov = {const_cast<void *>(data), len};
-  return this->write_raw_slow_(&iov, 1, len, sent);
-}
-
-// Multi-buffer slow path: handles partial writes, errors, and overflow buffering.
+// Slow path: handles partial writes, errors, and overflow buffering.
 // Called when the inline fast path in the header couldn't complete the write.
 // sent == -1 means either the fast path write returned -1, or there was overflow backlog.
 APIError APIFrameHelper::write_raw_slow_(const struct iovec *iov, int iovcnt, uint16_t total_write_len, ssize_t sent) {
diff --git a/esphome/components/api/api_frame_helper.h b/esphome/components/api/api_frame_helper.h
index f8f9bf81ef2..d9bd5efa373 100644
--- a/esphome/components/api/api_frame_helper.h
+++ b/esphome/components/api/api_frame_helper.h
@@ -200,7 +200,8 @@ class APIFrameHelper {
       if (sent == static_cast<ssize_t>(len)) [[likely]]
         return APIError::OK;
     }
-    return this->write_raw_slow_(data, len, sent);
+    struct iovec iov = {const_cast<void *>(data), len};
+    return this->write_raw_slow_(&iov, 1, len, sent);
   }
   inline APIError ESPHOME_ALWAYS_INLINE write_raw_fast_(const struct iovec *iov, int iovcnt, uint16_t total_write_len) {
     ssize_t sent = -1;
@@ -212,9 +213,7 @@ class APIFrameHelper {
     return this->write_raw_slow_(iov, iovcnt, total_write_len, sent);
   }
 
-  // Write methods — used by cold paths (handshake, error handling)
-  // These go through the slow path directly, avoiding inlining the fast path at the call site.
-  APIError write_raw_slow_(const void *data, uint16_t len, ssize_t sent);
+  // Slow path (out-of-line): handle partial writes, errors, overflow buffering
   APIError write_raw_slow_(const struct iovec *iov, int iovcnt, uint16_t total_write_len, ssize_t sent);
 
   // Socket ownership (4 bytes on 32-bit, 8 bytes on 64-bit)
diff --git a/esphome/components/api/api_frame_helper_noise.cpp b/esphome/components/api/api_frame_helper_noise.cpp
index 4b8b2f97069..150a110eb32 100644
--- a/esphome/components/api/api_frame_helper_noise.cpp
+++ b/esphome/components/api/api_frame_helper_noise.cpp
@@ -540,7 +540,8 @@ APIError APINoiseFrameHelper::write_frame_(const uint8_t *data, uint16_t len) {
   header[2] = (uint8_t) len;
 
   if (len == 0) {
-    return this->write_raw_slow_(header, 3, -1);
+    struct iovec iov = {header, 3};
+    return this->write_raw_slow_(&iov, 1, 3, -1);
   }
   struct iovec iov[2];
   iov[0].iov_base = header;
diff --git a/esphome/components/api/api_frame_helper_plaintext.cpp b/esphome/components/api/api_frame_helper_plaintext.cpp
index cb97f9d3942..5a887801d55 100644
--- a/esphome/components/api/api_frame_helper_plaintext.cpp
+++ b/esphome/components/api/api_frame_helper_plaintext.cpp
@@ -219,11 +219,13 @@ APIError APIPlaintextFrameHelper::read_packet(ReadPacketBuffer *buffer) {
                                                 "Bad indicator byte";
       char msg[INDICATOR_MSG_SIZE];
       memcpy_P(msg, MSG_PROGMEM, INDICATOR_MSG_SIZE);
-      this->write_raw_slow_(msg, INDICATOR_MSG_SIZE, -1);
+      struct iovec iov = {msg, INDICATOR_MSG_SIZE};
+      this->write_raw_slow_(&iov, 1, INDICATOR_MSG_SIZE, -1);
 #else
       static const char MSG[] = "\x00"
                                 "Bad indicator byte";
-      this->write_raw_slow_(MSG, INDICATOR_MSG_SIZE, -1);
+      struct iovec iov = {const_cast<char *>(MSG), INDICATOR_MSG_SIZE};
+      this->write_raw_slow_(&iov, 1, INDICATOR_MSG_SIZE, -1);
 #endif
     }
     return aerr;